Traps

Traps are special squares in quests that will give you a malus once you step on them. Difficult quests tend to have more traps than easier ones. It is possible to nullify their effect by bringing units that possess a trap counter passive skill. Be aware though that traps also have levels and an unit might not be able to counter a trap if its level is too high.

and are currently the only units able to counter every trap.