there are two types of combat encounters special and regular encounters.
regular encounters are fights against normal enemies. combat will happen in this order the enemies then your party. each member of your party will have 2 actions. enemy actions will vary.

special encounters will happen when you are fighting powerful foes. combat here will happen in order of initiative which will rolled every turn, then your attacks will happen in order of initiative. your party will start with one actions and can be increased to 3 actions a turn. enemy actions vary

other combat related topics
sanity clashing sin affinity status effects