Traps, Stealths and Ability Cards
Traps
are invisible objects that are placed on a field the owner has
conquered and that are triggered when an opponents card walks over
them. Until triggered, the opponent neither sees that a card was
played, nor that energy was paid. Traps are discarded when triggered. Stealth Cards
are similar to traps as they also stay hidden for the opponent after
being activated. A Stealth Card has a certain triggering event that causes
the cards effect to activate automatically (regardless of which players turn it
is), after which the Stealth is revealed and discarded. Abilities
work just like spells, however they are learned when drawn just like
evolutions or fusions. That means their effects can be activated
without discarding the card (they still have costs).