UU Game Terminology - Optional

From Unstable Games Wiki

Effects can be Optional, these are defined by using the word "may" in the text effect. ("If this card is in your Stable at the beginning of your turn, you may STEAL a Unicorn.").

Mandatory vs. Optional Effects
Some effects are mandatory (ex."DISCARD a card"), while others are optional ("you may STEAL a Unicorn"). If a card does not use the word "may," you can assume it is mandatory.


If a card has an optional effect that states "If this card is in your Stable at the beginning of your turn," you man NOT use that effect if you forget to use it before you DRAW a card for your Draw phase. If the effect is mandatory, you must still do it if you (or another player) notices that you did not use the effect.
If a card says "then," you may only perform the second action if you successfully perform the first action.
The Requirement is fulfilled even if the first action effect is replaced by another effect instead.
If a card says "If you do," only perform the second action if you choose to perform the first action.
The Requirement is fulfilled only when the first action effect resolves.

Gameplay Terminology