Combat will start when you attack an enemy or when you are attacked. All characters will get a chance to perform their actions based on their statistics. Some characters will act before others, and so on. There are two ways combat can start. You can initiate it, or someone else can. Combat in Fallout Universe is in turn-based. The way it works is that your character gets a chance to act, then the next person does all of his actions, and then the next person and so on. When everyone has had a chance to act, the turn is over and the whole thing starts over again at the top. The Sequence of the combatant will determine who will have the upper hand or who will act first. Each combatant, starting at the top of the list and working down, gets a chance to act. When everyone has gone, it starts all over again at the top of the list. The combat turn will end when everyone else is dead or they have fled.

Combat turn will usually only start combat if they are hostile, or if you really anger them by doing something they hate. Anyway you look at it, once combat starts, you'd better be prepared to end it. Regardless of whoever starts combat, all combatants (people participating in the battle, includes you) may act on their sequence. The critter with the highest Sequence gets to go first, then the critter with the next best Sequence and so on. Ties are determined by the best Agility, and if that is still tied, the best Luck. If it is still tied at that point, then the player who is tied for that position. There is no need to roll for initiative because they are ordered in a list by the Sequence statistic. Each turn of combat is five seconds of game time.

A combat can also be initiated by surprise attack. Whoever that has successfully surprise the other party by means of ambush or by just luck, get a free combat turn before returning to the normal sequence initiative list. Combat turn will not start if player ambush or sneak and kill the enemy using melee weapon or mere unarmed combat before the enemy's sequence. However, if you fail to surprise the enemy then they will get the free combat turn. Thus, think carefully before acting on it.