Unstable Weapons are weapons that do not have the same effects each time they are used. For example, a weapon that could deal low heat damage one turn and deal high heat damage the next turn. Here are some possible effects:
Unstable weapons can only be found by defeating boss mechs (e.g God Mode) or (rarely) from completing Hard/Insane campaign levels at level 30 only.
These new unpredicable weapons could add a new level of strategy to battles, where players have to think carefully before they use an unstable weapon, especially if the possible negative effects could decide the outcome of a battle. This idea could be expanded upon with new damage types and possibly unstable floor buffs.