Not every tileset has triggered traps. Not every tileset has fire traps. Some tilesets don't even have water. Yet, more often than not, you might still need e.g. a triggered trap on the Fire tileset. So which do you pick, from the multitude of traps we have now?
Especially with traps (or also teleporters?), the speed is relevant as well. The chameleon from ONML Rock is infamous for being the fastest triggered trap in the game. Maybe you have a Rock level, but the chameleon is simply too fast, and the vine trap not fitting visually in this specific position the trap is supposed to go in. In that case, I think another amphibious creature would be very happy to eat the lemming in place of the chameleon instead!
I'll limit my choices for borrowed objects to add to the official tilesets for the time being, but feel free to make specific suggestions for borrowed objects from or added to custom tilesets as well!
Dirt: triggered traps: L2 Highland Flower, L2 Outdoor Frog, ONML Chameleon, ONML Vine
fire areas: orig_fire pit
water areas: ONML Rock, L2 Cavelem
Pillar:triggered traps:
fire areas: orig_fire pit
Marble: triggered traps: L2 Egyptian horizontal Mashers, orig_pillar Spike trap (to prevent climbing long, thin poles)
Crystal: fire areas: GigaLem Metal Mod laser traps, namida Sky lightning traps
Fire: triggered traps: Dirt Bear trap, Crystal Golden-Plate trap, Crystal Electrocuting trap, L2 Cavelem Red-Eyes trap, ONML Brick Squisher, ONML Brick Disk Saw
Menace (Gronkling): triggered traps: Dirt Bear trap, L2 Cavelem Red-Eyes trap
Beast II (Gronkling): triggered traps: Menace (Gronkling) Snake
water areas: L2 Cavelem
Brick: triggered traps: Dirt 10-Tons-Weight, Crystal Electrocuting trap, Crystal Slicer trap, Bubble Suction trap
fire areas: orig_marble Slasher trap (although the colour doesn't quite fit), namida Lab "Acid"
water areas: orig_crystal, orig_dirt / orig_pillar
Rock: triggered traps: L2 Outdoor Frog, Menace (Gronkling) Snake, Beast II (Gronkling) Squirrel, Raymanni Sewer Crocodile
fire areas: namida Lab "Acid"
water areas: orig_marble, L2 Cavelem, L3 Biolab
Bubble: triggered traps: ONML Brick Squisher trap
water areas: namida Honeycomb
Snow / X-Mas: triggered traps: L2 Polar Ice Cube
fire traps: orig_fire blue fire traps (by Colorful Arty)
L2 Beach: triggered traps: Raymanni Sewer Crocodile, both the Quicksand and the "Sand Avalanche" from namida Desert / GigaLem Desert Mod
L2 Egyptian: triggered traps: L2 Beach Clam, Raymanni Sewer Crocodile, both the Quicksand and the "Sand Avalanche" from namida Desert / GigaLem Desert Mod
L2 Outdoor: triggered traps: ONML Rock Chameleon, ONML Rock Vine, Menace (Gronkling) Snake, Beast II (Gronkling) Squirrel, nin10doadict Cat
water areas: ONML Rock "Swamp"
L2 Medieval: triggered traps: the Knight trap from tan dx's Helloween tileset!
, plus there are these one-use traps of falling swords, don't remember from which tileset, sadly
fire areas: IchoTolot Castle (fire area with the bricks underneath)
L2 Classic: see Pillar
L2 Circus: triggered traps: Raymanni Circus "High-Striker" trap, nin10doadict Cat (like a white circus tiger...
)
fire areas: orig_fire
water areas: Raymanni Circus "Pool", L2 Sports, orig_dirt / pillar
L2 Highland: triggered traps: ONML Rock Chameleon, ONML Vine, Menace (Gronkling) Snake, Beast II (Gronkling) Squirrel
water areas: L2 Cavelem, ONML Rock "Swamp"
L2 Polar: triggered traps: orig_crystal Slicer
fire areas: orig_fire blue fire traps (by Colorful Arty)
L2 Space: triggered traps: all from orig_crystal
fire areas: namida Metal laser traps, GigaLem Metal Mod laser traps, namida Lab "Acid"
water areas: L2 Sports
L2 Cavelem: triggered traps: Menace (Gronkling) Snake, Beast (Gronkling) Squirrel
L2 Shadow: triggered traps: L2 Cavelem Red-Eyes trap (more clearly visible against the blue background!)
L2 Sports: triggered traps: Raymanni's green "Slime" trap (don't remember from which of his tilesets), L3 Biolab "Hammer" trap, ONML Brick Squisher, ONML Bubble Suction, ONML Rock Vine, Dirt 10-Tons-Weight, Dirt Bear trap
fire areas: GigaLem Metal Mod laser traps
L3 Biolab: triggered traps: Raymanni's green "Slime" trap
fire areas: namida Lab "Acid"
L3 Egyptian / Shadow: I've never actually used these yet...
Overall, I'd say the absence of trigger traps in orig_fire, the absence of fire areas in orig_crystal, the absence of water areas in L2 space, and especially the absence of both triggered traps and fire areas (aside from the "Tennis Ball") in L2 sports comes up most frequently for me.
Although the water from ONML Brick also has a particularly stupid animation that often makes these objects look way higher than the trigger area actually is. Basically, whenever you place ONML Brick water in a comparatively shallow pit, the waves will go over the edge of that pit, and look as if they were hitting an invisible vertical wall.
Coincidentally, there are also some traps that surprisingly do not fit into seemingly similar tilesets - like, for example, the Snow Spike from the ONML Snow / X-Mas tileset, which doesn't go well with L2 Polar, due to ONML Snow being more green-ish, and L2 Polar being more blue-ish. I've already discussed this to some extent in the thread "
Tilesets that go together well".
Finally, there's the purely game-mechanical issue of making straight walls Climber-proof. Sometimes you also need deadly objects here to disincentivise a Glider from using a wall to bump off it and turn around. The number of traps available for this task is very limited, with the Pillar Spike trap basically being the only triggered one, and the namida Metal / GigaLem Metal Mod laser traps and the namida Sky Lightning traps being the only fire areas I am aware of.
I'll probably also expand this list at some point with regard to my choices for more fringe-use objects, like teleporters, one-use traps, locked exits / buttons, splitters etc.
Feel free to add yours!
