Some spells require you to maintain [[Concentration]] in order to keep their magic active. If you lose concentration, such a spell ends. If a spell must be maintained with concentration, that fact appears in its [Duration] entry, and the spell specifies how long you can concentrate on it. You can end [[Concentration]] at any time (no action required). Normal activity, such as moving and attacking, doesn't interfere with concentration. [The following factors can break concentration:] - **[Casting another spell that requires concentration.]** You lose concentration on a spell if you cast another spell that requires concentration. You can't concentrate on two spells at once. - **[Taking damage.]** Whenever you 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. The DM might also decide that [certain environmental phenomena], such as a wave crashing over you while you're on a storm-tossed ship, require you to succeed on a DC 10 Constitution saving throw to maintain concentration on a spell.