Stunts generally give one benefit and have one limit. All stunts must be approved by the GM.
Gain +2 when using a skill with a certain action (attack, defend, overcome, create advantage)
Gain +1 when using a skill with all actions.
Use a skill in place of another skill.
Use a skill beyond it's normal limits (e.g. cast spells with Lore).
Gain an additional mild consequence slot.
Gain a +3 instead of a +2 when invoking a certain kind of aspect.
Gain a free invoke on a specific aspect.
Declare some story detail.
Add a rules exception.
An ally may use your skill in place of their own.
Provide a +1 bonus to allies in a specific zone.
Gain Weapon:2 or Armor:2