Concentration

Rules Index

Concentration is one of the main limits placed on ongoing magical effects. It prevents casters from stacking too many sustained benefits or control spells at once, and it makes battlefield pressure matter to spellcasters in a concrete way.

Only one concentration effect at a time. Beginning a new concentration spell ends the previous one immediately, even if the older spell still had duration remaining.
Cause What happens
Starting another concentration spellThe old effect ends immediately.
Taking damage and failing the saveThe concentration effect ends as soon as the check is failed.
Becoming incapacitatedThe caster can no longer maintain the effect.
Choosing to stopThe caster can voluntarily drop concentration at any time.

Concentration ties power to vulnerability. A strong ongoing spell is not just a benefit; it is also a tactical burden that encourages enemies to pressure the caster.

Position protects magic. The best place for a concentrating caster is often not the same place they would choose if all spells were fire-and-forget.

Damage is not the only threat. Forced movement, line changes, and incapacitating effects can all functionally dismantle a spell plan.