Concentration can be broken in a few ways in DnD 5e:

1. Taking damage: Whenever you take damage while concentrating on a spell, you must make a Constitution saving throw to maintain concentration. The DC for this saving throw is equal to 10 or half the damage you took (rounded down), whichever is higher.

2. Casting another concentration spell: If you start casting a new concentration spell, the current spell you’re concentrating on immediately ends.

3. Using a concentration feature: Some subclasses have features that read “as if you were concentrating on a spell” — using one of these immediately ends concentration on a spell or other such feature (Jeremy Crawford). The same goes for magic items that cast spells that require concentration to maintain.

4. Being incapacitated or killed: If you become incapacitated or die, you automatically lose concentration on any spells you were maintaining. Becoming paralyzed, stunned, unconscious, or petrified also causes you to become incapacitated, thus ending your concentration.

5. Environmental effects: The DM can rule that something like “a wave crashing over you while you’re on a storm-tossed ship” requires a DC 10 concentration check. Similar circumstances could include an earthquake, a strong gust of wind, or being swept away by a forceful current (PHB 203).

6. Some spells: Some spells have direction interactions with concentration:

   • Sleet Storm. 3rd-level Conjuration spell that forces concentration checks (DC is spell save DC of caster) for any caster in the area who’s currently concentrating on a spell.

   • Earthquake. 8th-level Evocation spell that forces concentration checks (DC is spell save DC of caster) for any caster in the area who’s currently concentrating on a spell.

   • Storm of Vengeance. 9th-level Conjuration spell that forces regular environmental factor concentration checks (DC 10) from rounds 5-10 of being conjured.

7. Casting a spell with a casting time longer than 1 action, including rituals. “When you cast a spell with a casting time longer than a single action or reaction, you must spend your action each turn casting the spell, and you must maintain your concentration while you do so” (PHB 202).

https://www.dndbeyond.com/sources/basic-rules/spellcasting#LongerCastingTimes

A creature can also “end concentration at any time (no concentration required).”

Player’s Handbook, Chapter 10: Spellcasting, pages 202-3

What Doesn’t Break Concentration in DnD 5e?

• Casting a spell that doesn’t require concentration

• Taking a short rest (as long as you don’t sleep and become unconscious)

• Losing line of sight of the concentration spell’s target

Matt Zane

Author, DnD Lounge

Matt Zane started DnD Lounge in 2021. Matt began playing DnD 5e in 2015, and has been DMing since 2017. He loves optimization, but also enjoys looking for creative ways to use spells and abilities that follow the spirit and letter of the rules. He also eschews pure optimization in favor of a more balanced approach, where building a character is primarily about serving an interesting story arc and party dynamics rather than maxing out DPR.