At present, the plan is to not allow a lemming to be both a Neutral and a Rival.
Do you have deneutralizers? What happens when you neutralize a rival, then deneutralize him: Will he be regular lemming or rival?
Had a bit of a brainwave today regarding this.
Neutrals currently count as +1 in a normal Exit and -1 in a Rival Exit. However, if we allow Neutrals to count as +1 in both Exits, then it might be OK to allow Rivals to become Neutrals. Furthermore, this scenario also makes more sense from a general gameplay point-of-view (i.e. Neutral lems shouldn't care which Exit they're in,
because they're Neutral).
So then, assuming the NL 12.XX Neutralizer & De-neutralizer objects work as I imagine they do (I haven't implemented or tested them code-side yet), a Rival that becomes a Neutral and is then De-neutralized will become a Rival again (i.e. we won't remove the Rival tag from the lemming).
If this goes ahead, Neutral will have to be the "preferred" state if a lem is given both tags. This will then render them un-assignable to, save-able in both Exit types, and only
potentially a Rival iff the level provides a De-neutralizer.
Given all current mechanics, and what could reasonably be expected from the game as "normal" behaviour, this seems to be the best way to handle the presence of both Rivals and Neutrals in the same level (and, indeed, the same lemming).
