All damage has a type which indicates the nature of that damage. Usually, the damage type does not matter when it comes to dealing damage to targets, but some effects and abilities interact with damage types.

Sentinels of the Multiverse uses the following damage types:

- Cold

- Energy

- Fire

- Infernal

- Lightning

- Melee

- Projectile

- Psychic

- Radiant

- Sonic

- Toxic

Damage can be irreducible, regardless of its type. Irreducible damage cannot be reduced by any effect, but it can still be increased or redirected. Damage can also be fixed, meaning it cannot be increased, reduced, or redirected. Additionally, fixed damage cannot have its type changed, such as from melee to fire, or psychic to toxic. If a target is immune to damage, or if an effect prevents damage to a target entirely, neither irreducible nor fixed damage can be dealt to that target.