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Lix => Lix Main => Topic started by: Simon on January 07, 2016, 09:54:30 AM

Title: Spawn interval fixed per level
Post by: Simon on January 07, 2016, 09:54:30 AM
Hi,

tl;dr:

Spawn interval (SI), a.k.a. release rate, should be fixed per-level. Can't change SI during play. Find counter-arguments: Suggest levels that can't be adapted with runners, jumpers, initial/required, or other features in Lix.

Why remove variable spawn interval (SI)?

Variable SI doesn't fit into the game design.

You control lems/lix by clicking on them, assigning skills. Right now, there are two extra ways to affect solutions: The nuke, and variable SI. In practice, the nuke assigns skills for you. Variable SI is an oddball, it affects lix-independent level variables.

The level author sets external variables, the player assigns skills.

Lix already allows the player to adjust spacing between lix, by walker/jumper/runner assignments. Each works differently than variable SI, but supports the game core much better. Supporting the core while solving a problem, that's the correct direction in game design.

Spawn-interval-changing solutions are prone to trial-and-error. Several players (Clam, NaOH, myself) consider SI-changing solutions less fun.

Replacements for variable SI
What levels can't be adapted?

We have about 500 levels. My claim is that most of them can be adapted.

I believe the strongest counter-arguments (= arguments for keeping variable SI) will emerge from discussion of some existing levels, and how they use variable SI.

Proxima's earlier list of levels where the spawn interval is part of the intended solution:
I would like to investigate these with Proxima, and with people who have solved them.

Everybody, suggest levels that can't be adapted well with other Lix mechanics, and would lose lots of their spirit.

When effective?

I don't want to change the C++ version. If I pursue fixed-only SI further, it would become a feature of the D port. So, nothing would change in the upcoming months.

Previous discussions

Discoverable UI (scrolling, dir select) (http://www.lemmingsforums.net/index.php?topic=2155), where I presented the idea to the forum for the first time. Fixing SI was a proposed solution to something else, there.

Proxima suggested in here the 5 levels from the list above.

IRC: Clam, Simon, 2015-12-12 (http://www.nordicbots.com/?id=73&net=quakenet&cid=81576&year=2015&month=12&day=12)

<Clam> I'd happily do without spawn interval being changeable in-game
<Clam> use FFF and don't have ridiculous amounts of rodents in the level

[...]
<SimonN> the variable SI is a fucking bug
<SimonN> heavy heavy bug, and there is a simple argument for it, about why it doesn't belong in this game
<SimonN> you control lemmings by skill assignments


IRC: NaOH, Proxima, Simon, 2015-12-20 (http://www.nordicbots.com/?id=73&net=quakenet&cid=81576&year=2015&month=12&day=21)

<Proxima> Speaking as someone who's done a lot of challenges, it's a tool I use all the time
<Proxima> though of course, the point of challenges is always to do as well as you can with the tools available, removing a tool changes the game but doesn't make it impossible to challenge yourself
<NaOH> I have seen that it is very useful when attempting pixel-precise tricks
<NaOH> But I feel guilty when I use it somehow.
<SimonMath> this is dangerous :)
<SimonMath> basher staircases were removed on a similar hunch, with great effect eventually, but that wasn't all expected
<NaOH> I feel much much more guilty with basher staircases :3


IRC: geoo, Ramon, Simon, 2016-01-06 (http://www.nordicbots.com/?id=73&net=quakenet&cid=81576&year=2016&month=1&day=6)

<SimonN> ARRRRRR, who wants to guess what feature I want to kill from Lix
<SimonN> With exciting new reasons, too
<SimonN> Cull, cull, cull. Summon ccx! Rise like a phoenix from deallocated memory and let us argue!

[...]
<SimonN> what affects physics, but is not assigning skills?
<Ramond__> something the player does?
<SimonN> yes
<Ramond__> wow no idea. there must be some hidden stuff I didn't know about
<SimonN> you can assign skills to make stuff happen differently, we agree on this?
<Ramond__> yes
<Ramond__> ...
<Ramond__> oh no...
<Ramond__> NO
<Ramond__> YOU DON'T MEAN
<Ramond__> NOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOoooo


-- Simon
Title: Re: Spawn interval fixed per level
Post by: Proxima on January 07, 2016, 06:09:11 PM
I'll reply to the general arguments at greater length when I have time. For now, a quick look at the specified levels.

Detailed discussion follows in spoiler tags, as it reveals several intended solutions. A brief summary:

* Most levels will be okay with fixed SI.
* The main exception is levels with a time limit, where fixing the SI would prevent enough lix spawning.
* Compression Method 2, The Hotel in Hell and The Continuum Hypothesis have other problems, which may be fixable.
* As a separate issue, Buridan's Lix should have initial SI raised to 60 due to new digger behaviour.

Spoiler (click to show/hide)
Title: Re: Spawn interval fixed per level
Post by: Proxima on January 07, 2016, 06:49:01 PM
The Hotel in Hell works with a fixed spawn interval with the following changes:

Spawn interval 52 (unchanged)
Skillset: 5 walkers, 1 floater, 1 imploder (no blockers), 5 builders, 5 bashers
3 minutes
Save 27/30
Title: Re: Spawn interval fixed per level
Post by: Nepster on January 07, 2016, 07:02:00 PM
A summary at the beginning:
I believe that most, but not all, levels can be adapted. However SI-changes are a feature to help players with executing their solutions and removing this feature will only move the difficulty/annoyance to other game elements or even newly create such difficulties.

Replacements for variable SI
Example levels (with a few additions):
Spoiler (click to show/hide)
It should be noted that most example levels only require setting the SI to 4 at some point and possibly back to the original SI again. This is relatively easily done, so any fix to allow constant SI could easily make the level much more difficult.
Title: Re: Spawn interval fixed per level
Post by: Proxima on January 07, 2016, 07:10:43 PM
As Nepster surmises, my suggested "fix" for The Hotel in Hell centres around making a close variant of the original intended solution work. I don't mind that there are other ways to solve the level (so long as there is no trivial solution) but I'm not that concerned about whether all the various solutions that have been found remain possible.

In case any backroutes turn up with the new version, here is another alternative (actually, in some ways I prefer this one):

Spawn interval 52
Skillset: 2 walkers, 2 floaters, 2 imploders, 2 blockers, 5 builders, 5 bashers
No time limit
Save 25/30
Title: Re: Spawn interval fixed per level
Post by: Simon on January 07, 2016, 07:51:29 PM
Thanks for the exhaustive studies of individual levels, and general ideas. I know that Proxima would like to give another general argument these days, for keeping variable-SI.

The levels' designers can tell best how close in spirit an adaption is. I like Proxima's Hotel in Hell with unlimited time, any intended route seems to take long anyway.

I agree with Nepster on how mass-suicide feels shaky and uncomfortable, let's try to avoid it. Another idea to adapt: Place several hatches, stacking all but one. The stacked hatches will spawn a crowd that follows the few workers spawned from the lone hatch.

Over the Hump, I'll take a look at it. I know how its basic idea is straightforward, I have solved this in the past. Interesting that such a seemingly-streamlined level poses adaption difficulties.

Breaking a single level is OK, violating general principles is not.

-- Simon
Title: Re: Spawn interval fixed per level
Post by: Nepster on January 07, 2016, 08:07:11 PM
Do I really need to post a rant about how bad stacking hatches is? :lix-glare: If players see two hatches, then they expect that both are used alternatingly, nothing else.
Title: Re: Spawn interval fixed per level
Post by: Proxima on January 07, 2016, 08:13:42 PM
To keep everything together, here's Nepster's list from the older topic:

Quote
After a closer look, the following levels require RR-changes:
S19, C19, C30, D10, D19, V2, V7, V28, V29, H4, H12, H25, H31, H34
(and perhaps some more Hopeless levels that I haven't solved yet)

There are quite a few more, where it helps (sometimes depending on your solution):
S21, Q11, Q19, Q31, Q37, C5, C14, C17, C23, C27, C37, D4, D6, D13, D25, V9, V10, V17, V21, V25, H2, H16

(Some levels may have changed position since this list was made?) Assuming level numbers are the same as in my copy of 2014-07-02, here are some comments on my own levels that are on this list:

S21 (Lix Potion Number Nine) -- While it's intended that you can solve the level by setting SI to 4 and not assigning any skills, perhaps this is a bit cheap, and requiring the player to find ways around the traps is more interesting.
Q31 (Prelude) -- Should not need any SI changes.
C23 (Come on down to my place) -- Same.
C27 (Compression Method 2) -- In spite of what I said above, Nepster is correct to list this as "where it helps" rather than "required". The given initial SI of 20 does allow merging with a particular placement of the initial cubes.
V17 (Lixster Quadrille) -- Should not need any SI changes. [EDIT: This has a fixed spawn interval, so Nepster *must* have meant some other level.]
V21 (Thomas the Climber) and V25 (Buridan's Lix) -- Already discussed above. Both are fine with fixed SI.
V29 (Brute Fours) -- I can see where changing the SI helps, but I can also see a way to avoid it.
Title: Re: Spawn interval fixed per level
Post by: Simon on January 07, 2016, 08:17:54 PM
Quote
Do I really need to post a rant about how bad stacking hatches is?

Agree. The solution is to put the hatches close to each other instead. Lix's hatches are smaller than typical L1 hatches, this works well for small numbers, even without overlap. Anyway, listing ideas to fix levels won't get us ahead much -- I have to consider if and how much executional problems fixed-SI would impose on the player.

Link: Solution to Over the Hump that doesn't touch the spawn interval. (http://asdfasdf.ethz.ch/~simon/etc/overthehump-Simon-constant-SI16.txt) This wasn't done with too much precision, but maybe I got lucky, simply. In that case, we can always go from 29/30 to about 27/28, or speed up the SI by 1.

-- Simon
Title: Re: Spawn interval fixed per level
Post by: Nepster on January 07, 2016, 08:19:47 PM
And here are backroutes for both new versions of Hotel to Hell.
Test1 is Proxima's second suggestion. Note that the SI-change was only done to speed things up - it is not required.
Test2 is Proxima's first suggestion.

EDIT: I had another solution in mind for Over the Hump, likely from an earlier version (it used a blocker). So, yes, the current level is fine.
Title: Re: Spawn interval fixed per level
Post by: Proxima on January 07, 2016, 08:33:14 PM
Nice work  :lix-grin:  For the first (no blockers) version, how about setting bashers to 3? (No version ever actually used more than 3 in the intended solution, the 5 bashers were just there for symmetry.)
Title: Re: Spawn interval fixed per level
Post by: Nepster on January 07, 2016, 08:43:51 PM
How about this solution: 28 Lix saved, 1 walker and 2 bashers spare and one pixel-precise basher assignment.
Title: Re: Spawn interval fixed per level
Post by: Proxima on January 07, 2016, 08:48:56 PM
Excellent. Like your 39/40 in Brute Fours, I regard that as a minor variation of the intended solution and not a backroute.
Title: Re: Spawn interval fixed per level
Post by: Nepster on January 07, 2016, 09:55:51 PM
Just found a completely different 29 Lix solution.
Title: Re: Spawn interval fixed per level
Post by: ccexplore on January 07, 2016, 09:59:08 PM
I feel like there hasn't been sufficient argument presented as to why this couldn't simply be left to the level designer's discretion as it is today.  Most levels probably don't need variable SI and the level designer may well already restrict the range of SIs anyway for backroute-avoidance purposes.  Time limits are best avoided generally speaking, and the number of levels where it serves a good purpose are perhaps few, but we have managed not to cull that out yet.  Variable SI feels very much like in that vein to me.

I'll concede that even the historic evidence suggests the game designers at DMA do not value variable SI as a level solving tool, starting with the fact that they removed it as soon as they got to Lemmings 2, and IIRC it didn't make a reappearance until Lemmings Revolution (not sure if Lemmings 3D has it), though in that game you actually get to control the SI for individual entrances (because lemmings don't alternate across entrances, they come out in parallel).  It seems very likely that it was originally conceived merely as a poor version of fast forward, though as more levels are developed for the L1 game mechanics, even the original games' level designers have caught on to ways of using it more as part of the level's solution.

Yes, if the level requires fiddly, precise changes of SI it wouldn't be too fun.  Then again, the same is true when a level requires a lot of precision moves with skill assignments.  Bridge stretching for example.  We handle these issues by recommending best practices for level designs.

I just feel like it's a little strange to cull away a gameplay feature that, while perhaps not that crucial overall, would seem to eliminate otherwise fine levels in the original game like "Just a Minute (Part II)" and "Flow Control".
Title: Re: Spawn interval fixed per level
Post by: Simon on January 08, 2016, 08:46:28 AM
Thanks for the response. Gave me lots of opportunity for reflection. After sleeping over it, I feel I can dissect it fully. >_>;

Quote from: ccx
why this couldn't simply be left to the level designer's discretion as it is today.

It is an unfitting feature that has not been pulling its weight.

To go from the game with everywhere-fixed SI to one with rarely-used variable SI, we incur these costs:

1. Allow the player to change the world in a new way, unlike anything else in the game. We may be used to it because L1 has it, but the difference of variable SI to skill assignments is glaring. If wanted, I can elaborate on the value of simplicity and conciseness in game design.

2. Make two buttons in the game UI, and display the current value. The buttons alone are highly nontrivial, taking left and right clicks. Setting a number freely in a game is UI bloat -- this is what city simulation games offer, or "Myliege, how much grain do thou wish to distribute to thy peasants?"

3. Introduce these buttons to new players. There is a ton of problems hidden here that have been bugging me for years.
4. Force even experienced players to check another level environment setting -- whether or not the SI is variable -- each time they play a level.

5. Make a second setting in the editor that depends on another editor setting, and must be changed along with it. (UI improvement would be a checkmark in the editor for fixed/variable SI, fixed by default. But this doesn't leverage any other numbered reason or bullet point, and it a rather high amount of work compared to the benefits.)

What benefits do we get?

Levels don't need variable spawn interval to be solvable. Even if they were thought to need it, they don't need it, or can be adapted surprisingly easily.

An exception are levels where SI fiddling is absolutely the main idea. And here, I value game design over pulling along every bit of accumulated tradition. If only 5 levels out of 500 would have to be culled, it's already a success.

Nepster has claimed how it helps execution. Yes, if the level designer can speculate on the player using SI, the level designer is less inclined to ease execution otherwise. I would like to see levels that can't be adapted accordingly.

So, the variable SI brings way less than the time limit -- unless unfixable levels are dug up, all we lose are the very few levels designed explicitly around SI changing. Its cost is much higher, and doesn't afford this.

Quote from: ccx
We handle these issues by recommending best practices for level designs.

Time limit: This isn't a method to affect the world as a player, which is the main reason I want to get rid of variable SI. As discussed, I have claimed this has more benefits in return, at lower cost. Also, I'd compare "all levels have unlimited time" closer to "all levels have SI 32" than "all levels have a fixed SI".

Builder stretching: Allowing builder stretching in the physics is simpler than disallowing it. Disallowing variable SI, or disallowing time limits, removes complexity from code, and from the player's mental model. But disallowing builder stretching would introduce code that checks for how long a walker has been walking since being a shrugger last, and then disallow builder assignments here.

Alternatively, the shrugger would have to walk to the tip of the brigde before shrugging. I've considered this before, I have shunned it due to looks and tradition.

Quote from: ccx
I'll concede that even the historic evidence suggests the game designers at DMA do not value variable SI as a level solving tool, starting with the fact that they removed it as soon as they got to Lemmings 2

Hmm, L2 and L3 don't have it. They don't make up for crowd control too nicely, but that's an issue with level design and other game features.

Lemmings 3D and Lemmings Revolution weren't designed by the same team anymore.

I assert that the two teams behind L3D and LR fell into the same trap as most developers of Lemmings-like games: Copying features from L1 without reflecting on their merits.

Quote from: ccx
eliminate otherwise fine levels in the original game like "Just a Minute (Part II)" and "Flow Control".

Flow control can be fixed with runners and longer walkways. :-) Just a minute 2, I'd have to take a look.

I'm not trying to cull variable SI from Lemmings 1, but from Lix, where there are better features for the desired effects.

-- Simon

PS. Conundrum can be adapted by
Spoiler (click to show/hide)
Title: Re: Spawn interval fixed per level
Post by: ccexplore on January 08, 2016, 08:15:41 PM
Well, it was clearly going to be an uphill battle arguing for keeping variable SI, given that it is definitely not used often throughout the history of both official games and custom levels.  I think I gave my best shot at playing devil's advocate for variable SI (and of course there's always NeoLemmix to continue doing things that are deemed too anti-lix ;P).  It is a good point that the desired effect for variable SI is usually to selectively compress a few rodents or to get some to come out (and therefore getting to certain places) sooner than the normal flow, but those things can often be arranged instead via skill assignments, and doing it those ways may arguably be even more interesting for the level's solution.

For those who are looking at adjusting existing levels accordingly, do keep in mind that runners can be somewhat more powerful than the effects of variable SI due to permanence of the skill, so make sure to also think about whether the changes may introduce new backroutes.

And don't forget to check your timed levels.  If the time limit expects the ability to minimize the SI towards the end, you may now need a longer time limit instead, and that may introduce backroutes as well.
Title: Re: Spawn interval fixed per level
Post by: Nepster on January 08, 2016, 09:09:11 PM
Quote
Nepster has claimed how it helps execution. Yes, if the level designer can speculate on the player using SI, the level designer is less inclined to ease execution otherwise. I would like to see levels that can't be adapted accordingly.
In any sufficiently complex system (such as Lix), you can remove any non-essential part and still adapt everything. E.g. you could remove all time limits or all traps or all other objects like springs, steams, ... or the ability to rotate terrain pieces or level wrapping or... Nothing essential would have to change!
The main point is not, that SI changes cannot be removed, but that they help level creators and players.

To get you some data, I manually went through (most of) the collected replays for the community level pack (version 2015-06-22, viewed with an old version of Lix) to look for replays where SI changes are an essential part of the player's solution, but were not needed in other (respectively intended) solutions. Here is the list:
Spoiler (click to show/hide)

Quote
To go from the game with everywhere-fixed SI to one with rarely-used variable SI, we incur these costs: ...
If anything, points 2 and 3 are bad UI and not an intrinsic problem of SI changes. And it's not that bad in my opinion - you display ingame help texts!
Point 4 doesn't hold because players will have to look at the SI even when it is fixed.
Point 5 I don't understand: Assume no SI change is required in a level. Why is fixing the SI then better than allowing changes?

Quote
Flow control can be fixed with runners and longer walkways.
There you have the same problem as with We're in this one together: I would rather change the SI than find the correct placement for the runners. We changed the bombers to untimed ones to remove placement problems, so why reintroduce them?


One more point: If you are creating a game without level editor, then you can expect that the level creators are experts and impose such restrictions like fixed SI, ... Experts like us here will surely find a way around it.
But having a level editor, you want to give everyone enough different tools to make their desired level. And SI-changes is one tool here that simplifies the level creation process. And I prefer people creating levels with SI-changes (even when the level can be modified to remove them) over people getting frustrated that they cannot produce a level featuring their level idea. Or they would create levels needing very precise skill assignments. I must confess that two years ago, I would have kept the old version of Heed the Traffic Light even with the current mechanics and fixed SI - just try it and see what I mean :lix-evil:.


Suggestion: Why not keeping SI-changes possible, but try to modify all current levels so that one doesn't need that feature? Then players may choose whether they prefer SI-changes or solutions via better skill usage.
Title: Re: Spawn interval fixed per level
Post by: ccexplore on January 08, 2016, 11:53:11 PM
I think the main tension here may be that unlike past game mechanic changes that have since been incorporated, this is the first time (at least as far as I can recall) we are proposing here a game mechanics change that isn't actively solving an existing problem provably experienced by actual players.  ("Here" because Simon certainly have had many other proposals on IRC that have yet to reach the point of a forum discussion thread. :P)  And the ability to vary SI can definitely be very powerful, giving you quite precise control over the flow of rodents with 0 costs and almost no side effects (neither of which would be true with skill usages).  So it makes sense that the option to vary the SI can be helpful from time to time, and can be appealing for some levels to require its use.  At the same time, it clearly is not of much help in the construction of an actual path to the exit unlike the core skills that modify terrain, so it is also no surprise that most levels don't need it.
Title: Re: Spawn interval fixed per level
Post by: Simon on January 09, 2016, 12:18:00 AM
Nepster, thanks for making the list to try.

I'll be meeting with Icho tomorrow, he's gonna show me a couple more examples of his own.

I've begun going through the suggested replays. Here's my results for the first 5 levels, and Pesky Gap. My interpretation: The players use the variable SI because it's available, but it doesn't make their solution easier to execute. Every time, once the solution idea is formed, were the players subjected to fixed SI, they'd have executed the idea similarly fast and precisely. Concrete reasons for this interpretation:

Spoiler (click to show/hide)

I found this general argument of yours to pull most weight:

Quote
There you have the same problem as with We're in this one together: I would rather change the SI than find the correct placement for the runners. We changed the bombers to untimed ones to remove placement problems, so why reintroduce them?

This is an excellent point. Is it applicable to levels other than mostly-SI-centric levels, which I don't care about much?

Quote
But having a level editor, you want to give everyone enough different tools to make their desired level.

When a level requires too much precision, it sucks. People will complain to the level designer, and the level designer will improve. When several levels require finding out the correct SI first, they suck. People will complain at the level designer.

People should not accept badly-set SIs, even when they can change it during play. They should report the bad design.

Quote
If anything, points 2 and 3 are bad UI and not an intrinsic problem of SI changes. And it's not that bad in my opinion - you display ingame help texts!

No, it is worse than fixed SI. If you want variable SI, you have to implement it somehow. No matter what you do, it's more cluttered than no button at all.

Point 4: I don't mean that players need to look at the exact number. I mean that players need to look at whether or not the spawnint can be changed. If it's fixed, the exact number isn't relevant too much; you have to experiment in the level anyway.

Point 5: Fixing the spawnint makes the player concentrate on the core mechanic of the game, assigning skills to lixes. So far (5 levels of your list examined), I haven't seen a good example for how variable SI gives power or comfort over the well-designed fixed-SI version. If this holds true for the remainder of the list, then fixed spawnint is comparable to giving unlimited time, instead of an overly generous time limit: Less to worry about, without losing puzzle scope.

Quote
Suggestion:

We shouldn't give options that don't do anything useful, or are mere placebos. Again, this depends on further examination of your list; so far, I'd lump 5/5 use cases in the placebo category.

-- Simon
Title: Re: Spawn interval fixed per level
Post by: Simon on January 09, 2016, 12:47:44 AM
isn't actively solving an existing problem provably experienced by actual players.

NaOH and I feel awkward when relying on it during play. Unlike with the basher staircases, I've discussed my hunch a few times before being prompted by her around christmas 2015.

Other than that, you're right -- in particular, my argument wasn't built on that awkward feeling. The entire reasoning behind the proposal is different from previous mechanics discussions on the forums.

I find variable SI unnatural, but Icho, for example, believes it's a core part of the game, with low learning curve. Proxima may still post a write-up later. All proponents of the variable SI are level designers.

Clam suggests fixed SI, an interesting exception for a level designer. Mindless and ADmiral suggest fixed SI, too, having followed the discussion without being entrenched in level design themselves.

-- Simon
Title: Re: Spawn interval fixed per level
Post by: ccexplore on January 09, 2016, 03:11:58 AM
Variable SI is definitely not the "very core" of the game when you compare it to the terrain-altering skills, as aside from rare exceptions you almost always need the latter to build a path to the exit.  At best you can probably compare variable SI to the other skills like climbers etc. that are typically used to get selected lixes deviate from the flow of the crowd, usually to get to otherwise inaccessible places for building the path to exit for the crowd.

I can no longer remember exactly how I learned about changing the RR when I first played Lemmings 1, though I don't remember ever running into trouble due to not knowing it is possible--even though there is no explicit tutorial level for it, it works differently compared to assigned skills, and you do need to change the RR in order to solve some of the later levels in the game (almost always in conjunction with a tight time limit).  So I definitely see it as having an apparent low learning curve, and thus I don't think I will put as much weight as you do on some of the arguments you listed regarding how variable SI can be problematic.  (Granted, with the current design of the skills toolbar in lix, the buttons for changing SI are inevitably less discoverable starting from their smaller sizes.)

I think for the proponents, the main appeal is that what may appear initially to be a boring feature can actually be a quite useful and powerful level solving tool.  I think it also carries less side effects than having to add additional skills to allow the player to achieve the equivalent effects, as adding additional skills tend to risk opening up backroutes.  And it can be easier to use as Nepster points out in his comparison to changing bombers to untimed.  Even if there's just a single instance of a temporary SI-bump in the level (so presumably it isn't in the "too-SI-centric-for-Simon-to-care" category?), it will be inevitably easier to achieve the desired effect with varying the SI compare to working out by eye where a running Lix will meet with a walking Lix.  [Indeed, it seems if variable SI is to be replaced by giving additional skills, the player would probably prefer other skills instead to achieve clumping of the lixes, like maybe jumping, batting, walkers, air-bashing etc., as pretty much all other methods except for runners would allow you to achieve the desired distance between lixes ahead of time instead of having to time it (unless I'm missing something about how Simon's using runners as a substitute for variable SI in the various examples; admittedly I haven't really looked at most of those levels yet).]

It makes sense that all proponents of variable SI so far are level designers, as there seems to be no level design reason to advocate for elimination of variable SI, given that no one is forced to use variable SI today when designing levels.  Where people stand on this topic depends on the problems one perceives variable SI leads to when playing levels (or learning the game), weighed against the perceived benefits variable SI brings to level design and solution execution.  Someone who likes variable SI would naturally be less affected by the problems while more appreciative and preferential of the benefits.

Anyway, do you realistically expect that you may actually change your mind about this over an example level?  Given the relatively low number of levels where variable SI is even relevant, and the high weight you attach to the perceived benefits of fixed SI (and perceived problems of variable SI) that you've listed, I kind of have a hard time seeing the outcome for you of even any good examples being anything other than "eh, I can live with those few levels sacrificed".  Especially since I think that's essentially how I could justify for myself living with the elimination, and I certainly don't weight the problems of variable SI anywhere as severely as you do.

I'm not really a level designer.  I don't mind variable SI when used judiciously in level design, but I don't expect a huge loss in great levels if it is eliminated so I'm willing to live with its elimination.  Most likely the thing I'd miss most would be the act of lowering SI to finish the level and then hearing the resulting dense stream of exiting lixes--I think by years of habit I've come to associate that with the victory of successfully solving a level. ;P  (And I guess I do worry a little about what the experience would be like to execute those solutions where we try to substitute runners for variable SI.)
Title: Re: Spawn interval fixed per level
Post by: Simon on January 09, 2016, 11:51:46 AM
We're in this one together is a good nontrivial example.
Spoiler (click to show/hide)

Change of opinion from example levels: Lower probability than 3 days ago. When I made the thread, I expected more levels to pose design problems to remain solvable, keeping their spirit. That assumption turned out wrong. Then I expected more levels to rely on it for comfort. My small personal sample suggests there are few such levels.

Nonetheless, I want to look into Nepster's list further, and meet with Icho tonight.

-- Simon
Title: Re: Spawn interval fixed per level
Post by: Nepster on January 09, 2016, 12:54:48 PM
I keep repeating myself, but my list of replays above is NOT a list of solutions/levels that cannot be adapted, once the possibility of these solutions is known to the level creator. The problem is, that when creating the level first, level creators will not know about such solutions and therefore won't adapt their levels to make the unkown solutions easy to execute. So most of the levels in the list above wouldn't have been designed differently if SI-changes were impossible. However the solutions mentioned above will become either very fiddly or impossible.
A prime example is Labyrinth of Despair: The replays use SI-changes to get another Lix close to a climber to bat her somewhere. The level can be very easily adapted by adding a few runners. On the other hand one can fiddle around without changing the SI to achieve the same result. In addition to that, there are solutions requiring no SI change at all. So it would have not been clear to me (would I have been the level creator) that runners should be added.
Title: Re: Spawn interval fixed per level
Post by: Proxima on January 09, 2016, 01:23:06 PM
There's a very clear reason not to add runners: it would make it possible for a runner-climber-jumper to clear that gap without any assistance.
Title: Re: Spawn interval fixed per level
Post by: Simon on January 09, 2016, 01:24:27 PM
@Nepster: So the argument is: We encourage level designers to make easy the execution of alternate accepted solutions. Variable SI is less prone to backroutes than runners, therefore the level designer is more inclined to give variable SI than extra runners.

This rests on the assumption that runners introduce more backroutes than variable SI.

There has been a Lemmings 1 level designing tradition for over 15 years, with lots of experience about what kind of backroutes come from variable SI. There is comparatively little judgement with how runners affect backroutes.

Level designers are reluctant to give runners, no matter whether they introduce backroutes or not, merely because they are a skill. The intuition is that giving extra skills is bad. This is a psychological hurdle [not always, there is something to it, see Labyrinth of Despair below], even if well motivated from Lemmings. 5 years ago, level designers have given strict time limits, just to be sure. It turned out that many weren't needed, damaged the playing experience, and designers have understood that.

Side issue: For optimizing solutions, variable SI doesn't cost anything, but runners are included in the total skill count. Whoever optimizes solutions goes through incredible pains with precision. This is independent of what tools there are; fidgeting with variable SI only adds to the pain, due to its many settings that affect very little.

@Proxima: Thanks for pointing out counterexample, will examine the level again.

-- Simon
Title: Re: Spawn interval fixed per level
Post by: Nepster on January 09, 2016, 02:50:31 PM
Quote
@Nepster: So the argument is:...
Yes, essentially this.
And remember that SI-changes are by default available and can be turned off when creating backroutes. Whereas runners, ... are by default not available and have to be added when needed or helpful. As the majority of levels does not have backroutes created by SI-changes (or equivalent features), I would prefer to have this available on default (similar to: Unlimited time is default, but it can be changed).

Proxima: Good point regarding Labyrinth of Despair. Completely missed this!
Title: Re: Spawn interval fixed per level
Post by: Simon on January 09, 2016, 03:02:21 PM
Yes, that too has been my next thought. As said to Proxima in IRC right now:

<SimonN> Nepster's argument is how variable SI helps solutions that aren't even known yet, because it is a comparatively gentle tool
<SimonN> with value for the player first, and only secondly for the designer
<SimonN> I find this the most substantial argument so far
<SimonN> and this is very hard to prove with examples, because it caters to yet-unknown solutions, especially of such open-ended levels
<SimonN> one possible answer to level designers is (give runners, unless backroute, then remove them); similar to (give unlimited time, unless backroute that is hard-to-fix otherwise, then impose time limit)
<SimonN> the problem here, which is very sad from my standpoint, is that (unlimited time is simpler than limited time), but (no runners) is simpler than (10 runners or something in every level)


Also on IRC right now: Insane Steve agrees that my impression of We're in this one together's core idea is correct, and other things are secondary to that. On the other hand, I was very direct with this special question, and haven't had let him read the entire thread so far.

Back to helping unknown solutions: Is there any method to measure how prevalent this is? What portion is affected with variable SI? Even with variable SI, people often come back to the designer and say "This is very fiddly, I hope you haven't intended this."

<SimonN> I estimate that I won't make the decision in the upcoming days
<Proxima> good, that gives me more time to formulate my thoughts :P
<SimonN> my hunch is that Nepster overestimates the value of VSI for the player, but I don't want to assert it, because he's done much more level design than I have


-- Simon
Title: Re: Spawn interval fixed per level
Post by: namida on January 10, 2016, 03:44:21 AM
Could one possible solution be to make the SI variable, but not to such fine degrees? For example, have it as a matter of "0 lix space between spawns", "1 lix space between spawns", etc?
Title: Re: Spawn interval fixed per level
Post by: Simon on January 11, 2016, 01:00:13 PM
I will postpone this decision for several weeks.

There is Nepster's value for unknown accepted solutions. Proxima would like to post pro-VSI arguments at some time, and I could elaborate further on game-design problems.

I've seen some levels at Icho's that use variable SI creatively and cleanly at the same time, but I've also seen levels where he could have picked a much better default SI. Variable SI for level designers is neither a pure win nor clear loss, measured in the quality of built levels.

Coarsely-variable SI (that can only take certain values) seems to combine the loss of no-variable-SI with the usability/game-design problems of variable SI. Toggling between RR 99 and the slowest-possible SI fares a bit better instead of setting a number.

I'm a little bit exhausted, because the other proponents of everywhere-fixed-SI haven't posted at all yet. Maybe it's convenient to let me do all the front-line work, but I will forget, misvalue, or misrepresent pro-fixed-SI arguments, too.

-- Simon
Title: Re: Spawn interval fixed per level
Post by: ccexplore on January 11, 2016, 08:18:35 PM
Level designers are reluctant to give runners, no matter whether they introduce backroutes or not, merely because they are a skill. The intuition is that giving extra skills is bad. This is a psychological hurdle [not always, there is something to it, see Labyrinth of Despair below], even if well motivated from Lemmings.

I can't speak for all level designers, but surely, given the abundant historical evidence that level designers themselves tend to miss backroutes that eventually found by others, and adding a skill at minimum forces a re-checking of the level for backroutes, this reluctance is a little more than psychology, compare to your analogy with time limits.  The best that can be said is that runners probably enable less unanticipated actions compare to other skills.

It is also fair to point out that explicitly giving skills may provide more of a hint to the player compare to variable SI, though arguably that is more due to a longstanding tradition of leaving the SI variable.

Incidentally, have people personally tried out executing those updated solutions using runners?  Nepster suggested that it might feel like going from untimed to timed bombers, it might be worthwhile to see if others feel the same in practice.

I'm a little bit exhausted, because the other proponents of everywhere-fixed-SI haven't posted at all yet. Maybe it's convenient to let me do all the front-line work, but I will forget, misvalue, or misrepresent pro-fixed-SI arguments, too.

I kind of feel like you already posted most if not all of the arguments to be said for pro fixed-SI.  Since pretty much everyone here have already experienced variable SI, there's little personal experience to draw from or resonate with in terms of the positives of never having to deal with it.  Meaning they can agree to some of those positives in principle, but would not feel as strongly about them as things they have actually experienced in the past.  Proponents can talk about and resonate experience-wise with some of the bad things enabled by variable SI, but then you'd still need to bring up the additional arguments to support elimination over merely discouraging use of variable SI.

But yes, if there are some pro-fixed-SI arguments that someone feels Simon has not yet done justice to, let's hear it. 8-)
Title: Re: Spawn interval fixed per level
Post by: Simon on January 13, 2016, 10:32:21 PM
Update from IRC yesterday. "VSI" == variable spawn interval, either per level, or as a game feature to allow it. In case it's unclear which of the two is meant, ask.

Visibility: In a level with VSI, VSI should become more visible/pronounced in the user interface. Right now, VSI doesn't look like an important feature, but sometimes, it is critically important. This is a mismatch.

Announce rare time limit: I would like to have a big, flashy warning on starting a singleplayer level with time limit. No-time-limit is the norm, but time limits occur often enough to become very annoying if unnoticed.

Announce rare VSI: If level designers allow VSI only where it's required or probably helpful, VSI levels should get a similar warning, or really obvious UI support for VSI. I believe this is unnatural, but namida wouldn't find it that strange.

Make pack work with/without VSI: I see Nepster's suggestion as an improvement over the status quo: If it's easy to design a level without requiring VSI, then make it solvable with the default SI. Most levels in the community pack can be easily adapted. The solution isn't always runners, it's often much simpler.

No replacement: Spawn interval cannot be replaced 1-to-1 with skills. There is no equivalent.  Runners replace only one use case, and have their own drawbacks. 1-to-1 translation to skills would mean skills like "stall faller/walker that has just come from the hatch", which introduce extra mechanics that, like VSI, clash with the game design of "every interaction is a skill, you get to choose almost freely to whom to assign".

Trampolines: Neither Proxima nor I like these too much, they behave strangely and defy intuition. They fit better into the game than VSI, because they're purely reactive to lixes, not introducing new player-lix interaction. I'd be neutral or moderately happy to remove them. They're used in 2 lemforum levels, 2 Clam levels, 3 Rubix levels. In multiplayer, trampolines haven't spiced up levels, only made stupid levels more stupid. But that would be material for a new thread.

Still pro-fixed-SI: I continue to believe that culling SI is a bit healthier than Nepster's suggestion. We offer anti-frustration by high-performance framestepping and by deprecating unnecessary pixel precision. Yes, level design would change slightly, because VSI is not the easy route out of designing clustering anymore. Finding the appropriate SI becomes a job of the level designer instead of the player.

-- Simon
Title: Re: Spawn interval fixed per level
Post by: Proxima on February 09, 2016, 08:43:20 PM
So, as I said, I want to reply to the general argument, rather than focusing on specific levels. It's true that a couple of levels don't work with fixed SI (The Hotel in Hell can probably be fixed even though the fixes suggested so far have been shown not to work; The Continuum Hypothesis certainly doesn't work without drastic changes). Still, I'm not convinced by the general argument that removing VSI is a good thing and the individual levels that don't work are the main problems standing in the way.

The main "anti" argument seems to be that VSI isn't the "core" of gameplay. But in the first place, it's not easy to say what the core of a game is. And many games have supporting features that are not part of the core, but make the game more enjoyable, whether it's by adding variety or aiding usability or both: bombs in Touhou, powerups in Super Mario World, bonus stages in Sonic, etc.

As for Lemmings and Lix, while giving skills to lemmings is certainly part of the core, so too is the fact that they wander back and forth when not performing skills. That immediately makes spacing important. This article, recently linked on the forums (http://readonlymemory.vg/the-making-of-lemmings/), suggests that the makers considered traps part of the core, and setting SI to compress two lemmings so only one is killed is a major mechanism for getting past a trap.

But really, the main question should be whether keeping VSI makes the game, overall, more enjoyable or not. I do agree that fiddling about with the SI to get a particular spacing can be a bit irksome. But Nepster makes a good point: fiddling about with skills can be as bad or worse. And it's not something you can really get away from, because altering spacing is an inherent part of the game, whether it's to get one lemming past a trap, give a builder enough space to finish building a bridge, get enough lemmings into a dig pit before it goes all the way down, and so on and so on. If you take away VSI as a tool for these things, players are going to have to do the same things with whatever tools they have left. Focusing the discussion on levels that cannot be solved without VSI misses the point that it aids on a lot of other levels. Changing SI is a relatively clean way to alter spacing, because if you can work out the spacing you need, you can just enter it as a number. While it's true that this is drastically different from interacting with lemmings by clicking on them, so too is framestepping to move the assignment of skills to an exact time, and that was judged to be a good thing to add to Lix to aid execution.

* * *

I also want to talk about discoverability. Simon's first point is correct: as-is, Lix's UI does not make it obvious what the SI buttons do. That is a reason for improving the UI, not (in itself) a good reason for removing the feature. I have suggested an icon of two lix with a double-headed arrow between, a standard symbol for "spacing".

Simon's second point, "They aren't needed in 98 % of the levels, and don't scream "use me" once they are", is thinking in the wrong direction. Lix is a puzzle game, and telling the player "this feature is needed for this puzzle" is providing a hint before they've even started thinking about the puzzle. It's as if we proposed to have every level start with the skill you need first already selected. Sure, it makes the program easier to use, and might sound on paper like a good idea, but it hurts the enjoyment of starting from a hintless puzzle and a given set of tools and working out for yourself which of those tools will help you solve the puzzle. If we solve the issue of making it more discoverable that VSI exists, then the issue of players being stuck because VSI is needed for such-and-such puzzle and they don't know it exists automatically goes away.

For the same reason, the suggestion to make fixed SI the norm and set the SI to variable only when needed for a level is absolutely terrible. First, it necessarily provides an unwanted hint; secondly, it takes away a tool that is often useful even when not necessarily required. The ability of level designers to fix SI on individual levels for backroute prevention is fine, but other than that, ultimately we have to decide whether we (as a whole, on balance) think the pros of VSI outweigh the cons or they do not; in which case VSI should either be fully allowed or never allowed.
Title: Re: Spawn interval fixed per level
Post by: Simon on February 09, 2016, 09:39:10 PM
Thanks for the detailed reply.

You're making a solid point for choosing one of two extremes: Either cull the VSI, or make it well-accessible and discoverable with improved buttons. As a player, changing the SI is free of charge. To embrace the VSI, then, authors should fix the SI only to prevent backroutes, similar to imposing time limits.

When Icho was with me 3 days ago, I played a new level by him. Had the SI been fixed, I would have solved it faster. I thought the level needed VSI when it did not. If we embrace VSI, we encourage authors to keep this red herring wherever possible. This is unlike other standard settings: Choosing no time limit, no skill of a certain type, no surprisingly low save requirement, etc., all these streamline the player's pathfinding.

Having default red herrings is not bad per se, because it's a puzzle game. It makes the game more complex, but it's not unfair.

I would like to distinguish VSI sharply from framestepping, because framestepping doesn't affect physics. Since we have always allowed text-editing replays, we don't gain more control by framestepping. It improves the user experience without touching the game design.

Framestepping is not an interaction with lemmings, VSI is. They're different fundamentally, and neither justifies existence of the other.

VSI remains odd: Either it's part of the core idea, otherwise there is nothing in the fixed-SI game that suggests adding VSI. While VSI influences the fundamental, important spacing between lemmings, so would teleportation.

Yeah, in the end, it boils down to staking out the underlying design, then supporting that in a powerful way.

-- Simon
Title: Re: Spawn interval fixed per level
Post by: Clam on February 10, 2016, 05:54:25 AM
It's not mentioned here, but Simon and I had a chat about this (http://nordicbots.com/?id=73&net=quakenet&cid=81576&year=2016&month=1&day=7) shortly before he started the topic. And when I first saw the topic, it already had a page full of replies, which I'll admit put me off posting, especailly since I'd given my views on IRC already. But it's more visible here, and I've thought of new things since. So:

I'm firmly in favour of culling variable spawn interval. And this is coming from a level designer :lix:.

My main problems with VSI:

Against culling VSI:

Effect on my levels if VSI is culled:
(Henceforth: FSI = fixed spawn interval, applied to a single level.)
I can definitely live with that. But in my case, the damage is spread thinner over more levels – I have roughy a "pack" worth anyway. I empathise with designers who lose a larger proportion of their levels to this.
Title: Re: Spawn interval fixed per level
Post by: Simon on February 11, 2016, 02:10:41 AM
Thanks for taking the time to reply in detail.

We have similar opinions and judgements on VSI. Nonetheless, it's valuable to distill a longer argument/opinion from IRC into a summarizing post.

I've claimed that the bad existing user interface for VSI is a reason to for everywhere-fixed SI. That wasn't a valid argument, because the user interface can be made better. You've focused purely on game design, that holds more water.

-- Simon
Title: Re: Spawn interval fixed per level
Post by: Proxima on February 11, 2016, 02:02:46 PM
I think it's worth pointing out, in reply to the earlier discussion in Clam's link, that L1 challenges often required extreme fine-tuning of RR, due to the sliding glitch. This is absent in Lix, and so far I have not observed any Lix levels requiring such fine-tuning or even suggesting that it would be helpful. SI precision is generally used either to space two particular lix, or to merge the entire crowd; in either case, finding a correct value only needs to be done once or twice in a solution.