Combat takes place on a seperate map, where up to 3 players and/or NPCs can face off against up to 3 others. You can join mid-combat, which means NPCs can join mid-combat too.
Rupture uses a turn-based model, where each battle takes place between two sides (Left and Right). Players/NPCs on a side all take their turn simultaneously, and then the other side. You have 30 seconds to perform actions with your units, before you run out of time and the turn switches to the other side.
All units have the basic 4 abilities of: Attack, Guard, Swap Position and Use Item. In addition to these 4, units may have up to 6 of their own abilities; abilities use up action points, which are partially regenerated at the start of every turn.
The Attack ability is the basic attack of every character; depending on the class, the range and amount of units hit may vary. Some can only attack the first unit in a row, while others will hit a straight line of units; some may attack flying units and others not.
All player parties have a 'main' character in their group of units. If that main character dies, the rest of that group automatically flees. Main characters are typically stronger than the rest, having access to more abilities than regular characters do.
Some attacks can be chained together to create combos; these are specific attack combinations from differently classed units, from the same group, during the same turn. The combo attack replaces the last attack in the chain with the combo.