Concentration
Some spells (and a few other effects) require you to maintain Concentration to keep their magic active over time, as noted in the spell's duration.
- You can concentrate on only one spell at a time. Casting a second spell that also requires Concentration ends your Concentration on the first.
- Concentration doesn't require an action, and you can otherwise act normally while concentrating. Casting a spell that does not require Concentration never breaks it.
- Taking damage: each time you take damage while concentrating, make a Constitution saving throw against a DC equal to 10 or half the damage taken (rounded down), whichever is higher. Resolve a separate save for each source of damage. On a failure, Concentration ends.
- Concentration also ends if you have the Incapacitated condition or you die.
- You can end your own Concentration at any time (no action required).