Assign a Character
You may assign a ready character to the current mission. He will slide upward on screen toward the current mission. (He is then no longer ready, he becomes assigned instead.)
You can assign a team character to the current mission even if his rating in the skill it requires is 0; you can assign a support character to the mission only if he has some rating in the required skill.
To complete the current mission during the next step, the total skills contributed by your assigned characters must be equal to or greater than its difficulty. Assigning characters is your means to ensure success.
Boost a Character
If you have a character card in your hand that has the same title as a character you have assigned to the current mission (even if it has a different subtitle), you may discard it from your hand. The assigned character gets skills +1 until the end of the current mission.
You may boost the same character more than once during the same mission.