Characters will often wish to help each other in a task. Whether it is kicking a door down or plotting an interstellar jump, there are advantages to having multiple people involved.
To cooperate in an action the characters must be able to communicate clearly with each other, plus have the time to work out a plan and coordinate their individual efforts. These restrictions prevent characters assisting each other in combat situations without the use of keywords such as Resistance. There is simply no time to effectively communicate and coordinate actions in battle.
Outside of combat, characters have the time to work together effectively in narrative actions. One character is nominated as the leader for the action. This is normally the best person at the task and it is from them everyone else takes their cues. Each character selects their cards, rolls their dice and the total score from all the characters involved is the action's score.
There is a drawback to working together.
Apart from the action's leader, the characters involved can play fewer cards as some of their attention and effort is spent reacting to the leader's actions. The first person after the leader can play one less card than normally allowed by a narrative action. For this action, their dynamic pool is considered one smaller than normal. The second person after the leader plays two cards fewer than normal, the third three cards fewer and so on down to a minimum of one card per character.
Any number of characters may be involved in an actions if the situation allows it. Five people trying to break down a door are likely to get in each other's way but if they have a battering ram or it is a very large door they may be successful. Situation bonuses may be awarded to the resistance if the characters' ability to work together is restricted.
Assisted actions take longer than normal because the characters have to spend time communicating the plan and coordinating their actions. Due to the chatter, it is also noisier. Anyone nearby should get situation bonuses to their awareness checks.