Card Traits
Some cards have traits which alter their behavior. These traits are represented by icons in the bottom right corner of the card.
Exhaust
When you play an Exhaust card, it goes into the exhaust pile instead of the discard pile. Under most circumstances, cards can't be retrieved from the exhaust pile, so they are effectively removed from your deck until the end of combat. This means that Exhaust cards can only be played once per fight, although they are usually quite powerful to compensate for this.
Single Use
Like Exhaust cards, Single Use cards can only be played once, with the difference being that they are permanently removed from your deck once played, and cannot be recovered.
Temporary
Temporary cards only last for one fight, as they are permanently removed from your deck at the end of combat. Most cards that are created in the middle of combat are Temporary.
Buoyant
Buoyant cards start at the top of the draw pile, and will be drawn first at the start of combat.
Retain
At the end of your turn, Retain cards will stay in your hand instead of being discarded. Keep in mind that they can still be discarded through other means.
Recycle
When you play a Recycle card, it goes back to the top of the draw pile instead of the discard pile. This allows you to repeatedly draw the card as long as you can keep playing it.
Infinite
Infinite cards do not discard when played, and will stay in your hand instead. They only leave your hand when otherwise discarded.
Discounted
Discounted cards will cost 1 less energy until they're played or until the end of combat, so this is only a temporary trait.
Flippable
Flippable cards can be right-clicked to reverse their directional actions from left to right and vice versa.
Dual Card
Dual Cards have two sets of actions, differentiated by the dividing line between them. The highlighted segment will be performed when the card is played, and you can right-click it to switch to the other half.
Unplayable
Pretty self-explanatory: if you try to play an Unplayable card, you won't be able to! This also means the only way to remove them from your hand is to either end your turn or discard/exhaust them with something else. Some Unplayable cards will have effects that apply when they're drawn or while they're in your hand, so these cards won't always do absolutely nothing.
This trait is displayed a little differently, with a red line through the energy cost rather than an icon on the bottom right of the card.