Concentration

Concentration is required for some abilities, such as dwarven and gnomish detection abilities, and for some spells, such as spiritual hammer.

The definition of concentration is not universally established in the rules. For example, the concentration required by phantasmal force is said to break upon movement,1) PHB 75. whereas the concentration required by improved phantasmal force allows half-MV.2) PHB 95.

It is suggested that the definition of concentration on this page be applied in general. When one of the items on this page contradict the spell description (or other specific rule), always favor the specific rule.

Ending

Concentration ends when:

The concentrating creature declares they are ceasing concentration.

The concentrating creature takes any action other than concentration, including any movement.3) Examples: PHB 75, “Phantasmal Force”, and DMG 44, “Wall Of Fire”. Remember that some spells say that some movement is possible, such as improved phantasmal force. Always favor the specific spell description or rule when one is given, ignoring the general rule on this page.

The concentrating creature takes damage.

The concentrating creature applies their dexterity modifier to armor class or a saving throw.

The concentrating creature is successfully unarmed-attacked, or makes an effort to resist such an attack.

The concentrating creature is attacked psionically.