Reactions

Figure 1 - Active Reactions. The dialogue bubble on each icon indicates that these reactions are set to "Ask".

Reactions are actions taken in response to a trigger, and can be taken even if triggered on another creature's turn.

Some reactions require the acting creature to expend a  Reaction resource, whereas other reactions do not. Those that do not are generally class features which use the reaction system, such as  Divine Smite,  Reckless Attack, or  Sneak Attack.

The Reactions tab

Figure 2 - Reactions Tab. Each reaction can be enabled or disabled with its corresponding checkbox on the left. They can be further configured with the 'Ask' setting to prompt the player for confirmation each time the reaction is triggered.

Reactions are managed for each character through the Reactions tab, located on the spellbook page of a character sheet. The tab can also be accessed immediately by pressing on one of the active reactions on the hotbar, or by pressing a hotkey (default: L).

Reactions can be set to be taken automatically, or the game can be set to prompt the player first.

If taking a reaction expends any resources, they are listed under the reaction's name.

Limitations

A character cannot apply more than one reaction to the same event if any of them prompt for confirmation; the UI prevents selecting more than one reaction per character.

The set of reactions triggered by an event are determined before any of them take effect. This means an attack roll or saving throw that would normally ignore a reaction (e.g., because the roll succeeded and the reaction is a roll bonus from an ally) ignores that reaction even if the roll outcome is changed by another reaction.

Consider these examples:

1. A character in range of an enemy casting a spell has both  Counterspell and  Psionic Backlash set to prompt for confirmation. Because both trigger on the same spellcasting event and require user input, the game engine forces a choice between them: the character cannot use Counterspell to negate the spell and Psionic Backlash to deal damage for the same event.
2. An ally rolls 16 against a DC 15 saving throw. Because the roll succeeds initially, a reaction that assists failed saves – such as a Wild Magic Sorcerer's  Bend Luck – is excluded from the reaction queue. If an enemy Bard then uses  Cutting Words to lower the roll to 13, causing a failure, Bend Luck still cannot be used because the set of available reactions was locked before any were resolved.

Events ignored by reactions

Reactions that trigger on damage or saving throws generally only trigger on the immediate, built-in effects of an action. Damage and saving throws are ignored by the reaction system if they originate from:

• Conditions, including surface and other area effects (e.g.,  Burning damage and saves to avoid slipping on ice or to end  Hold Person early are ignored)
• Explosions from grenades, barrels, or other items, excluding arrows and launched fireworks
• Most reactions that are not attacks or spells (e.g.,  Opportunity Attack and  Hellish Rebuke can trigger reactions, but not  Tenacity damage)
• Passive features (except as noted below)
• Special weapon hit effects ("weapon functors"), such as the save against  Silenced from Sussur weapons

Concentration saves and death saves are ignored.

Saving throws of passive features are ignored except for the following:

•  Reverberation
•  Oil of Bane and  Oil of Diminution coatings
•  Simple,  Serpent Fang,  Wyvern, and  Purple Worm toxin coatings
• Passive features granted by the following equipment:

•  Cindermoth Cloak
•  Clown Hammer
•  Dark Displacement Gloves
•  Flawed Helldusk Armour
•  Gontr Mael
•  Ichorous Gloves
•  Justiciar's Scimitar
•  Markoheshkir ( Acidic)
•  Mourning Frost
•  Nature's Snare
•  Poisoner's Gloves

• The following NPC passive features:

•  BOOOAL's Faithful
•  Caustic Strikes
•  Dazzling Blows
•  Fishfolk Faithful
•  Form of Dread
•  Grasp of the Forest
•  Infectious Madness
•  Infested
•  Tanglevine Form

Preventing reactions

Creatures can be prevented from taking many reactions by a number of conditions. These include:

• Any fleeing condition such as  Fearful
• Any incapacitating condition such as  Hold Person
• Any invisibility condition, which prevents all reactions besides  Accursed Spectre,  Blinding Ambush, and  Weird Magic Surge
• Any polymorph condition besides disguises and Starry Forms ^{[See: Bugs]}
• Any restraining condition such as  Ensnared
• Any stunning condition, namely  Stunned
• Any unconscious condition such as  Prone

Other conditions prevent creatures from spending  Reaction resources. These include:

•  Arms of Hadar
•  Dazed
•  Shocking Grasp
•  Slowed
•  Surprised

This latter set of conditions does not prevent affected creatures from taking reactions which do not consume the  Reaction resource. Such reactions notably include Legendary actions performed by bosses in Honour mode. These actions are triggered like reactions but use a different resource making them unaffected by these conditions.

List of all reactions

Reaction	Cost	Effects
Absorb Elements		Absorb elemental damage once per Short Rest. Take half damage from the next elemental attack targetting you, and deal an additional 1d6 of that element type on your next attack.
Accursed Spectre		Raise an Accursed Spectre from the soul of a fallen cursed target to fight by your side. The size of the fallen creature will determine whether you raise a  Feeble Spectre,  Mundane Spectre, or  Primordial Spectre. Doesn't work with constructs, elementals, oozes, plants, or undead.
Adamantine Reverberation		Grym's form vibrates after being struck, providing  10 temporary hit points and doubling its movement speed while the temporary hit points are present.
Armour of Hexes		When a creature you cursed with  Hexblade's Curse attacks you, potentially nullify the attack. This has a 50% chance of succeeding.
Bardic Attack		Add a +1d6 bonus to your  Attack Roll.
Bardic Defence		Add a +1d6 bonus to your  Saving Throw.
Bend Luck	+ 2	When an ally makes an  Attack Roll or  Saving Throw, it receives a +1d4 bonus.
Bend Luck	+ 2	When an enemy makes an  Attack Roll or  Saving Throw, it receives a -1d4 penalty.
Bulwark Rebuke		When a creature damages you, deal it 2d4⁠⁠Force and possibly knock it  Prone.
Charm		Charm an enemy that attacks you, preventing them from attacking you until their next turn.
Cloud of Jellyfish: Attack		Use your swarm to attack the same target and deal 1d6⁠⁠Lightning damage.
Cloud of Jellyfish: Mighty Shocking Sting		Use your swarm to  Shock and  Disarm your target.
Cloud of Jellyfish: Mighty Teleport		Use your swarm to  Teleport to a new location within 5 m (17 ft) and gain a temporary +2 bonus to your  Armour Class.
Cloud of Jellyfish: Shocking Sting		Use your swarm  Shock your target.
Cloud of Jellyfish: Teleport		Use your swarm to  Teleport you to a new location.
Controlled Chaos		Induce a  Wild Magic Surge on the nearby spellcaster.
Corpulent Rage		As your health diminishes, let out a bone-quaking roar that pushes back anyone near you, and go  Berserk.
Cosmic Omen of Weal: Attack Roll	+	Add a +1d6 bonus to an  Attack Roll.
Cosmic Omen of Weal: Saving Throw	+	Add a +1d6 bonus to a  Saving Throw.
Cosmic Omen of Woe: Attack Roll	+	Subtract 1d6 from an  Attack Roll.
Cosmic Omen of Woe: Saving Throw	+	Subtract 1d6 from a  Saving Throw.
Counterspell	+	Stop a spell from being cast. If it is higher level than the spell slot used to Counterspell, you must roll to prevent it.
Cunning Combo		"When you shoot a target at close range, you can make an additional melee attack against it as a  Reaction.
Curving Shot		Use a  Bonus Action to attack the next closest target with the same attack.
Cutting Words	+	The target receives a -1d6 penalty to  Attack Rolls,  Ability Checks or damage dealt.
Dampen Elements		When you or an ally gets hit with Acid, Cold, Fire, Lightning, or Thunder damage, you can use your reaction to halve the attack's damage.
Defensive Attack		At the start of a round, you can reduce the weapon's additional attack bonus by 1 to increase your  Armour Class and  Saving Throws by 1.
Defensive Duellist		When attacked with a melee attack, add your Proficiency Bonus to your  Armour Class, possibly causing attacks to miss.
Deflect Missiles		Reduce the damage from a ranged weapon attack by 1d10 + your Dexterity modifier + your monk level. If the damage is reduced to 0, you can use a  Ki Point to  Deflect the Missile.
Deflect Missiles: Redirect		Catch a projectile from a ranged weapon attack and shoot it back at your attacker using  Deflect Missiles: Redirect.
Destructive Wrath		When you roll Thunder or Lightning damage, you can use your  Channel Divinity Charge to deal maximum damage instead.
Divine Allegiance		When an ally within 1.5 m (5 ft) of you takes damage, you can use your  Reaction to magically substitute your own health for your ally's, healing them by 2 × (Paladin level)⁠⁠Hit Points at the cost of taking 2 × (Paladin level)⁠⁠Radiant damage yourself.
Divine Retaliation		Strike back at the enemy that attacked you or your ally.
Divine Smite		Your weapon deals an additional 2d8⁠⁠Radiant damage, increased by 1d8⁠⁠Radiant damage when attacking Fiends or Undead.
Divine Smite on Critical Hit		Your weapon deals an additional 4d8⁠⁠Radiant damage, increased by 2d8⁠⁠Radiant damage when attacking Fiends or Undead.
Divine Strike on Critical: Cold		Deal an additional 2d8⁠⁠Cold.
Divine Strike on Critical: Fire		Deal an additional 2d8⁠⁠Fire.
Divine Strike on Critical: Lightning		Deal an additional 2d8⁠⁠Lightning.
Divine Strike on Critical: Necrotic		Deal an additional 2d8⁠⁠Necrotic.
Divine Strike on Critical: Poison		Deal an additional 2d8⁠⁠Poison.
Divine Strike on Critical: Radiant		Deal an additional 2d8⁠⁠Radiant.
Divine Strike on Critical: Thunder		Deal an additional 2d8⁠⁠Thunder.
Divine Strike on Critical: Weapon (Melee)		Deal an additional 2d8⁠⁠Weapon.
Divine Strike on Critical: Weapon (Ranged)		Deal an additional 2d8⁠⁠Weapon.
Divine Strike: Cold		Deal an additional 1d8⁠⁠Cold.
Divine Strike: Fire		Deal an additional 1d8⁠⁠Fire.
Divine Strike: Lightning		Deal an additional 1d8⁠⁠Lightning.
Divine Strike: Necrotic		Deal an additional 2d8⁠⁠Necrotic.
Divine Strike: Poison		Deal an additional 1d8⁠⁠Poison.
Divine Strike: Radiant		Deal an additional 2d8⁠⁠Radiant.
Divine Strike: Thunder		Deal an additional 2d8⁠⁠Thunder.
Divine Strike: Weapon (Melee)		Deal an additional 1d8⁠⁠Weapon.
Divine Strike: Weapon (Ranged)		Deal an additional 1d8⁠⁠Weapon.
Drunkard's Luck	2	When you make an Ability Check, Attack Roll, or Saving Throw and have  Disadvantage on the roll, you can spend  2 Ki Points to negate the Disadvantage for that roll.
Elemental Affinity: Resistance		When you cast a spell that deals damage matching your draconic ancestry, you can spend 1  Sorcery Point to gain Resistance to that damage type.
Elemental Retort		When attacked, the affected entity can draw on Siphoned magic to cast  Elemental Retort.
Entropic Ward		Impose  Disadvantage on an  Attack Roll against you. If the attack misses, you gain  Advantage on your next Attack Roll against the attacker for 1 turn.
Executioner		Once per Long Rest when you kill a creature, your next  Attack Roll will be a Critical Hit.
Flurry of Moths: Attack		Use your swarm to attack the same target and deal 1d6⁠⁠Psychic damage.
Flurry of Moths: Blinding Swarm		Use your swarm to  Blind your target.
Flurry of Moths: Mighty Blinding Swarm		Use your swarm to  Blind and  Slow your target.
Flurry of Moths: Mighty Teleport		Use your swarm to  Teleport you to a new location within 5 m (17 ft) and gain a temporary +2 bonus to your  Armour Class.
Flurry of Moths: Teleport		Use your swarm to  Teleport you to a new location.
Giant Killer		If a Large or bigger creature attacks you, you can retaliate with a melee attack.
Githyanki Parry		Parry unarmed and weapon attacks to reduce their damage by 10.
Greater Kushigo Counter		The wearer can use their reaction to make an unarmed strike against any attacker that misses.
Guided Strike		Gain a +10 bonus to your  Attack Roll.
Heart of the Storm: Lightning		When you cast a spell of Level 1 or higher that deals ⁠Lightning damage, you cause a small, local storm. All enemies within 6 m (20 ft) take (Sorcerer level / 2)⁠⁠Lightning.
Heart of the Storm: Thunder		When you cast a spell of Level 1 or higher that deals ⁠Thunder damage, you cause a small, local storm. All enemies within 6 m (20 ft) take (Sorcerer level / 2)⁠⁠Thunder.
Hellish Rebuke	+	React to your next attacker with flames that deal 2d10⁠⁠Fire.
Illusory Self		Interpose an illusory duplicate of yourself between you and an attacker's strike, making them miss their attack.
Improved Warding Flare		Impose  Disadvantage on an ally's attacker, possibly causing their attack to miss.
Indomitable		Whenever you fail a  Saving Throw, you can roll again, using the new result instead.
Infernal Resistance		Once per Long Rest, when you fail a  Saving Throw, you may succeed instead.
Instinctive Charm		Charm an enemy attacking you. They will attack a new target if possible.
Interposing Protector		Strike back with  Selûne's Ire at an attacker with holy righteousness.
Kushigo Counter		While  Patient Defence is active: the wearer can use their reaction to make an unarmed strike against any attacker that misses.
Legendary Resistance		Increase your crowd control  Saving Throw result by 10.
Legendary Resistance		Increase your  Saving Throw result by 10.
Legion of Bees: Attack		Use your swarm to attack the same target and deal 1d6⁠⁠Piercing damage.
Legion of Bees: Knockback		Use your swarm to push your target back 5 m (17 ft)
Legion of Bees: Mighty Knockback		Use your swarm to push your target back 5 m (17 ft) and knock them  Prone.
Legion of Bees: Mighty Teleport		Use your swarm to  Teleport you to a new location.
Legion of Bees: Teleport		Use your swarm to  Teleport you to a new location.
Luck of the Far Realms		When you make a successful Attack Roll against a foe, you can change that hit into a Critical Hit.
Lucky: Reroll Attacker's Die		Spend a  Luck Point to force a creature to reroll its  Attack Roll.
Lucky: Reroll with Advantage		Spend a  Luck Point to gain  Advantage on your  Attack Roll,  Ability Check, or  Saving Throw.
Mage Slayer		Attack an enemy as a  Reaction if they cast a spell near you.
Missile Snaring		Reduce damage from a ranged weapon by 1d10 + your Dexterity Modifier.
Misty Escape		Upon taking damage, become  Invisible. On your next turn, you can cast  Misty Step, though this will break your invisibility.
Murderous Retort		Immediately strike back at an attacker. If  Deathbringer's Legacy is active, use  Deathbringer's Assault instead.
Opportunity Attack		Attack an enemy moving out of your reach.
Paralysing Critical		Once per Long Rest, when scoring a Critical Hit on a humanoid, you can  Paralyse the target for 2 turns.
Polearm Master: Opportunity Attack		Make an Opportunity Attack whenever a creature enters your reach.
Portent Die		Change the die of a nearby  Attack Roll or  Saving Throw to the portent die.
Projected Ward		When a nearby ally takes damage, you can use your Arcane Ward to reduce the damage equal to its charges and then lose 1 charge.
Protection		When you have a shield, impose  Disadvantage on an attack against your allies when you are within 1.5 m (5 ft). You must be able to see the attacker.
Psionic Backlash		When a nearby enemy casts a spell, you use your reaction to deal 1d4⁠⁠Psychic for every level of that spell.
Psionic Dominance		When an enemy within 18 m (60 ft) targets you with a spell of a Level that is lower than or equal to your Proficiency Bonus, you can use your reaction to nullify the spell.
Rakish Sneak Attack		Deal extra damage to a foe you have  Advantage against. You can also use this attack without Advantage if there are no other combatants within 2 m (7 ft) of the target, or if there are no other combatants within 5 m (17 ft) and you have an ally within that range.
Rakish Sneak Attack (Critical Hit)		Deal extra damage to a foe you have  Advantage against. You can also use this attack without Advantage if there are no other combatants within 2 m (7 ft) of the target, or if there are no other combatants within 5 m (17 ft) and you have an ally within that range.
Reckless Attack		Gain  Advantage on  Attack Rolls until the end of your turn, but enemies also have Advantage against you.
Redirect Attack	+	When a creature misses you with a melee attack, spend 1  Ki Point as a reaction to make them attack a new target if possible.
Right Behind You		When your warlock attacks a target, materialise next to that target.
Ring of Evasion		When you make a Dexterity  Saving Throw, you can use your reaction to succeed instead.
Riposte	+	When a creature misses you with a melee attack, you can retaliate with a powerful  Riposte that deals an additional 1d8 damage if you are wielding a melee weapon.
Scarab of Protection		Once per Long Rest, when you fail a  Saving Throw against necromancy spells or spells cast by undead foes, you can use your  Reaction to succeed instead.
Second Chance		Once per Long Rest, you can spend a  Reaction to make an  Attack Roll or  Saving Throw with  Advantage.
Self-Detonation Protocol		Initiate a countdown sequence that ends with  Self-Detonation.
Self-Detonation Protocol		Initiate a countdown sequence that ends with  Self-Detonation.
Sentinel		When an ally is attacked by a nearby creature, you may strike the attacker.
Shield	+	When you are about to be hit by an enemy, increase your  Armour Class by 5. You take no damage from  Magic Missile.
Shield Blow		When struck by a melee attack, your attacker must succeed a Dexterity  Saving Throw or fall  Prone.
Shield Master: Block		Shield yourself from a spell attack: when you fail a Dexterity  Saving Throw on a spell, you only take half damage. When you succeed, you take no damage.
Sneak Attack		Deal extra damage to a foe you have  Advantage against.
Sneak Attack (Critical Hit)		Deal extra damage to a foe you have  Advantage against.
Song of Defence: 1		Subtract 5 from incoming damage.
Song of Defence: 2		Subtract 10 from incoming damage.
Song of Defence: 3		Subtract 15 from incoming damage.
Song of Defence: 4		Subtract 20 from incoming damage.
Song of Defence: 5		Subtract 25 from incoming damage.
Song of Defence: 6		Subtract 30 from incoming damage.
Soul Catching Boon		Gain +5 bonus on your next  Attack Roll.
Soul Catching Prowess		Gain a +5 bonus on your next  Saving Throw.
Splinter Shadow		When you are attacked by a melee attack that does not deal Radiant damage, splinter off a piece of yourself to spawn a new version from the shadows.
Storm's Fury		When struck by a melee attack, you may deal Lightning damage to the attacker and possibly push them back.
Supreme Githyanki Parry		Parry unarmed and weapon attacks to reduce their damage by 20.
Tenacity		When you miss a melee attack, you deal Strength Modifier⁠⁠Bludgeoning damage (minimum of 1) anyway.
Tides of Chaos		Gain  Advantage on your next  Attack Roll,  Ability Check, or  Saving Throw. Increased chance of  Wild Magic surge afterwards.
Touch of Death		When hitting a creature with a melee attack,  Channel Divinity Charges can be used to deal extra ⁠Necrotic damage.
True Strike Riposte		When a creature misses you with a melee attack, you may retaliate and gain  True Strike.
Unflinching Protection		When your ally is about to be hit by a foe, you can use your  Reaction to make it automatically miss. Used once per Long Rest.
Unstable Backlash		While  Raging, when you take damage or fail a  Saving Throw, you trigger another Wild Magic effect. This replaces your current Wild Magic effect.
Valiant Attack		Add a +1d6 bonus to your  Attack Roll.
Valiant Damage		Add an additional +1d6 damage to your weapon attack.
Valiant Defence		Add a +1d6 bonus to your  Saving Throw or  Armour Class.
Vengeful Father		Increase Strength by 2 and gain Resistance to all physical damage.
War Caster: Opportunity Spell		Cast  Shocking Grasp at a creature moving out of range.
War God's Blessing	+	Grant a nearby ally a +10 bonus to their Attack Roll.
Warding Flare		Impose  Disadvantage on an attacker, possibly causing their attack to miss.
Withering Cut		When you hit a creature with melee weapon, you can spend a reaction to deal additional Necrotic damage equal to your Proficiency Bonus.
Wrath of the Storm: Lightning		If a nearby enemy attacks you, you can retaliate with  Wrath of the Storm: Lightning that deals 2d8⁠⁠Lightning.
Wrath of the Storm: Thunder		If a nearby enemy attacks you, you can retaliate with  Wrath of the Storm: Thunder that deals 2d8⁠⁠Thunder.

Bugs

• Reactions to saving throws ignore those for  Staggering,  Thunderous, and  Wrathful Smite and  Topple the Big Folk.
• Most reactions are normally disabled by form-changing conditions such as  Polymorphed and  Wild Shape (but not  Disguise Self or  Starry Form). However, they are erroneously enabled if the creature also has a Disguise or Starry Form condition at the same time.