A combat mode is a state characters can enter that affects combat in some way. Each provides some benefit while the mode is active, and some additionally exact a penalty, as described in each mode's article. The user interface for modes is a toggle; the radial menu or quickslot for turning them on is also the means for turning them off. If a combat mode is assigned to a quickslot, that slot is highlighted while the mode is active. Only one combat mode can be active at a time; when a combat mode becomes active, the previously active mode (if any) is first automatically deactivated.

When activated outside of combat, a combat mode becomes active right away, but when activated in combat, the mode becomes active at the start of the character's next combat round. In contrast, manually deactivating a combat mode takes effect right away, even in combat (with the exception that some mode effects will linger until the end of the round). Combat modes are automatically deactivated when a character takes a non-combat action (e.g. moving to a clicked location) and when a character leaves combat (e.g. the last enemy in range dies).

The combat modes in Neverwinter Nights are the following.