If a Spell must be maintained with Concentration, its description specifies how long you can concentrate on it. You can end concentration at any time (no action req). The following factors can break concentration:
- Casting another spell that requires concentration.
- Overwhelmed / damage. Whenever you are distracted or take damage while you are concentrating on a spell, you must make a Constitution saving throw to maintain your concentration. The DC equals 10 or half the damage you take, whichever number is higher. If you take damage from multiple sources, such as an arrow and a dragon’s breath, you make a separate saving throw for each source of damage.
- Being incapacitated or killed. You lose concentration on a spell if you are Incapacitated or if you die.
