Bonus Action Spellcasting 5e: Cantrips and Reactions
Few spellcasting rules create more table pauses than the phrase “bonus action.” I find the easiest solution is to stop counting spell levels and ask one question first: did anyone cast a spell as a bonus action this turn? In the 2014 rules, that is what activates the special restriction.
Bonus Action Spellcasting 5e: Quick Answer
Under the 2014 rules, after you cast any spell as a bonus action, the only other spell you can cast during that turn is a cantrip with a casting time of one action. The restriction applies whether the bonus-action spell is a leveled spell or a cantrip.
The rule does not say “one leveled spell per turn.” Without a bonus-action spell, features such as Action Surge can allow more than one leveled spell on the same turn, and a reaction spell can also occur on your turn when its trigger happens.
The 2014 Bonus-Action Spell Rule
A spell with a bonus-action casting time uses your one bonus action for the turn. Once you cast it, any other spell on that same turn must satisfy both requirements:
- It is a cantrip.
- Its casting time is one action.
For example, a cleric can cast healing word as a bonus action and sacred flame as an action. The cleric cannot cast healing word and then guiding bolt, because guiding bolt is not a cantrip.
The order does not provide a loophole. Casting the action spell first and the bonus-action spell second is still casting both on the same turn, so the combination must satisfy the restriction.
Bonus-Action Cantrips Still Trigger the Restriction
Spell level does not determine whether the 2014 rule applies. If a spell is cast as a bonus action, it triggers the restriction even when that spell is a cantrip.
A sorcerer using Quickened Spell to cast a cantrip as a bonus action therefore cannot cast a leveled spell with the action on that turn. The action spell must be another cantrip with a casting time of one action.
Can You Cast a Reaction Spell on the Same Turn?
Normally, yes. A reaction spell can be cast on your own turn if its trigger occurs. The official Sage Advice Compendium gives the classic example of a wizard casting a spell, an enemy answering with counterspell, and the first wizard using a reaction to cast counterspell in return.
However, a bonus-action spell changes that answer. Once you cast a spell as a bonus action, a reaction spell is not a cantrip with a casting time of one action, so you cannot cast that reaction spell during the same turn.
The restriction ends with the turn. If you cast healing word during your turn, you can still cast shield later in the round on someone else’s turn, provided you have your reaction and its trigger occurs.
Action Surge and Multiple Spells
Action Surge can give a fighter another action. Under the 2014 rules, a multiclass spellcaster can use those two actions to cast two leveled spells on the same turn because there is no general one-leveled-spell-per-turn rule.
That changes if the character also casts a bonus-action spell. Once the bonus-action spell is cast, every other spell on that turn must be a one-action cantrip. An extra action does not override the bonus-action restriction.
Example: Action Surge Without a Bonus-Action Spell
A fighter/wizard uses an action to cast fireball, uses Action Surge, and casts another action spell. That can be legal under the 2014 general rules because neither spell was cast as a bonus action.
Example: Quickened Spell and an Action
A sorcerer uses Quickened Spell to cast fireball as a bonus action. The sorcerer’s action can cast a one-action cantrip such as fire bolt, but not another leveled spell.
Activating an Existing Spell Is Not Casting It Again
Some spells are cast once and then allow a bonus action on later turns to move or control an effect. Taking that later bonus action is not casting the spell again unless the spell says it is.
The Sage Advice Compendium uses spiritual weapon as an example: casting it triggers the bonus-action spell restriction on that turn, but commanding the weapon with a bonus action on a later turn does not. On that later turn, the caster can use the action to cast a leveled spell normally.
Bonus Actions Are Not Extra Actions
A bonus action is a separate kind of action granted by a rule, spell, or feature. You cannot use an ordinary action to perform a bonus action, and you do not automatically have a menu of generic bonus actions.
You can take no more than one bonus action on a turn. If two features both require it, you must choose between them.
Bonus Action Spellcasting: 2014 vs. 2024 Rules
The 2024 rules replace the 2014 bonus-action-specific restriction with a broader limit: on a turn, you can expend only one spell slot to cast a spell. The casting time is no longer the central test.
That changes several combinations. In a 2024 game, Action Surge does not let a character expend two spell slots on the same turn. A cantrip and one spell cast with a slot can still work because only one spell slot is expended. A spell cast without expending a slot requires careful reading of the feature and the other spells used that turn.
Do not apply that one-slot rule to a 2014 game. For this site’s 2014 rules coverage, use the bonus-action procedure explained above.
Bonus Action Spell FAQ
Can you cast two cantrips in one turn?
Yes, when your features and casting times provide the needed action economy. A bonus-action cantrip plus a one-action cantrip is permitted by the 2014 bonus-action rule.
Can you cast healing word and shield on the same turn?
No. After casting healing word as a bonus action, shield does not meet the requirement of being a cantrip with a casting time of one action. You could still cast shield later on a different creature’s turn.
Can Quickened Spell let you cast two leveled spells?
No. Quickening one spell makes it a bonus-action spell, activating the restriction on every other spell cast that turn.
Does using a bonus-action class feature restrict spellcasting?
Not by itself. The special restriction applies when you cast a spell as a bonus action, not whenever you use any bonus action.