Reactions or Replacements - PHB
Barbarian
Path of the Berserker - Approach Me
When you reach 4th level, you gain the ability to retaliate against those who approach you in melee combat. During your rage, other creatures provoke an opportunity attack when they enter your reach.
Path of the Totem Warrior - Spectral Blessing
When you reach 4th level, you gain the ability to grant the blessing of your totem spirit to creatures near you. During yor rage, when a creature begins its turn within 30 feet of you, you may use your reaction to grant them a benefit until the end of their turn based on the totem animal you chose while gaining this feature. You may choose the same animal you selected at 3rd level or a different one.
Bear. Whenever the chosen creature makes an attack, they gain resistance against damage from melee attacks from that creature until the end of their next turn.
Eagle. Whenever the chosen creature makes an attack roll, they don't provoke opportunity attacks for the rest of the turn.
Wolf. Whenever the chosen creature makes a melee weapon attack, they gain a bonus to the damage roll equal to your Rage Damage.
Bard
College of Lore - Improved Cutting Words
When you reach 4th level, you no longer expend Bardic Inspiration when you use Cutting Words. Instead, you can use it a number of times equal to your Charisma modifier (a minimum of once). You regain all expended uses after a short or long rest.
College of Valor - Hit Harder
When you reach 4th level, you gain the ability to improve the strength of your allies' strikes. When a creature within 30 feet of you is hit by a weapon attack, you can use your reaction to give a bonus to the damage roll equal to half your Bard level.
Cleric
Knowledge Domain - Quick Recall
When you reach 4th level, you learn how to better apply your smarts to the battlefield. When a creature you can see and haven't used this feature on starts its turn within 60 feet, you may use your reaction to make a Knowledge check (DM's choice) to determine aspects of the creature. The DC is 10 + the creature's Challenge Rating, or Level if the creature has class levels. If you succeed, you learn the creature's AC, their highest saving throw, and any resistances, immunities, and vulnerabilities they may have.
Life Domain - Shield the Faithful
When you reach 4th level, your god grants you the ability to protect others from harm. When another creature within 30 feet of you takes damage, you may use your reaction to reduce that damage by half of your Cleric level, rounded up. This can't reduce the damage below zero.
Light Domain - Sun's Blessing
At 4th level, when you cast a spell of first level or higher that deals fire or radiant damage, you deal additional damage of that type equal to half of your Wisdom modifier, rounded up (minimum of 1).
Nature Domain - Abhor Unnatural
When you reach 4th level, your Channel Divinity: Turn Undead also works on the creature types aberration, celestial, elemental, fey, and fiend, in addition to undead.
Tempest Domain - Storm's Blessing
When you reach 4th level, when you cast a spell of first level or higher that deals lightning or thunder damage, you deal additional damage of that type equal to half of your Wisdom modifier, rounded up (minimum of 1).
Trickery Domain - Degrading Miss
When you reach 4th level, your god grants you the ability to affect others when they fail to draw your blood. When a creature within 30 feet of you misses you with an attack, you may use your reaction to impose disadvantage on that creature's attack rolls until the start of its next turn.
War Domain - Divine Defenses
When you reach 4th level, you gain the ability to invoke your god's power to prevent further harm to yourself. When a creature hits you with a weapon attack, you may use your reaction to add your Wisdom modifier to your AC for the rest of the turn.
Druid
Circle of the Land - Manipulate Terrain
When you reach 4th level, your connection with the land manifests in harsh winds, churned earth, and roiling sea near you. When a creature moves to an area within 15 feet of you, you may use you reaction to create difficult terrain in a sphere with a raidus of 15 feet centered on yourself until the end of the turn.
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Circle of the Moon - Feral Instincts
When you reach 4th level, your more animalistic instincts take over while wild-shaped. While wild-shaped, when a creature at maximum hit points takes damage, you may use your reaction to move up to your speed towards the creature. Then, if the creature is within your reach, you may make an opportunity attack against it.
Fighter
Champion - Strive for the Best
When you reach 4th level, your determination to be the best of the best makes sure no one can outshine you. When a creature other than you lands a critical hit, you may make one weapon attack with advantage as a reaction.
Battle Master - Face Me!
When you reach 4th level, you gain the ability to exploit the distractions of your enemies. As a bonus action, you can Mark a creature until that creature falls unconcious or you cannot see it. When a Marked creature makes an attack against a creature other than you, you may use your reaction to make a weapon attack against the Marked target. You may only have one creature Marked at once, and a creature may only be Marked by one creature.
Eldritch Knight - Spell Recognition
When you reach 4th level, you have some rudamentary understanding of defensive magic and can shield yourself with it. When a spell is cast by a creature within 5 feet of you, you may use your reaction to gain resistance to the damage of the spell this turn.
Monk
Keep Your Balance
When you reach 4th level, you can no longer be forced to move, teleport, or travel planes.
Paladin
Oath of Devotion - Protect the Good
When you reach 4th level, your loyalty an attention to your allies allows you to protect them in more and more ways. When a creature within 10 feet of you is hit with an attack, you may use your reaction to grant that creature the effects of sanctuary until the end of the turn.
Oath of the Ancients - Nature's Wrap
When you reach 4th level, your attunement with nature extends to protection of your allies. When an ally within 10 feet of you is hit with a melee attack, you may use your reaction to force the attacker to make a Strength saving throw versus your spell save DC. On a failed save, the attacker is restrained until the end of the turn as vines coil around the creature's body.
Oath of Vengeance - Answered Sleight
When you reach 4th level, you gain the ability to retaliate more effectively against those that would dare harm who you care about. When a creature within 10 feet of you is hit with a melee attack, you may use your reaction to move up to 10 feet and make a melee attack against the attacker, if able.
Ranger
Hunter - Turned Flank
When you reach 4th level, you gain the ability to more effectively take advantage of your target's weaknesses. When you hit a creature with a weapon attack, you may Mark that creature until the start of your next turn. While a creature is Marked in this way, if it makes an attack against any other creature than you, you may use your reaction to make a weapon attack against the Marked creature. You may only have one creature Marked at once, and a creature may only be Marked by one creature.
Beast Master - Beast's Bond
When you reach 4th level, your bond with your companion allows you to retaliate against those who wrong it. When a creature deals damage to your beast companion, you may use your reaction to make an attack against that creature.
Rogue
Thief - Nimble Swipe
When you reach 4th level, your nimble fingers allow you to disrupt others while fighting. When a hostile creature you can see moves out of your reach, you may use your reaction to try to swipe an object from the creature. If you do so, make a sleight of hand check contested by their athletics or acrobatics check. If you win, you can take an object from them that you could wield or put away with the Use an Object action. For example, you could take a weapon, arcane focus, or potion, but you could not take a shield or armor.
A creature can avoid provoking this reaction by taking the Disengage action. They also don’t provoke this reaction when they teleport or when someone or something moves them without using their movement, action, or reaction.
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Assassin - Lethal Pursuit
When you reach 4th level, when you make an opportunity attack against a creature you've damaged, you have advantage on the attack roll.
Arcane Trickster - Distracting Gesture
When you reach 4th level, you can manipulate your mage hand in more complex ways. When a creature within 5 feet of your mage hand casts a spell, you may use your reaction to attempt to break their incantation. If you do, make an ability check using your spellcasting ability contested by their concentration check. If you win, the creature's spell fails and has no effect.
Sorcerer
Draconic Bloodline - Elemental Infusion
When you reach 4th level, you can assist an ally by allowing them to tap into your elemental power. When a creature other than you damages an enemy, you may use your reaction to deal additional damage to that enemy. If the triggering damage is the type associated with your draconic ancestry, the additional damage is equal to your sorcerer level. Otherwise, the additional damage is equal to half of your sorcerer level, rounded up. Either way, the additional damage is the type associated with your draconic ancestry.
Wild Magic - Chaotic Energy
When you reach 4th level, you learn the spell chaos bolt if you don't already have it. Otherwise, learn another sorcerer spell.
When you cast chaos bolt, you may recover the spell slot used to cast it. Once you use this feature, you may not use it again until you finish a long rest.
Warlock
The Archfey - Drowsy Whispers
When you reach 4th level, you learn the spell sleep if you don't already have it. Otherwise, learn another sorcerer spell.
When you cast sleep, you may recover the spell slot used to cast it. Once you use this feature, you may not use it again until you finish a long rest.
The Fiend - Fiendish Retaliation
When you reach 4th level, you gain the ability to lash out at those who harm you. You can choose one damage type when you finish a short or long rest. When a creature hits you with a melee attack, you may use your reaction to deal damage to that creature of the chosen type. The amount of damage is equal to half of your warlock level, rounded up.
When you reach 10th level, you may choose the same or different damage types for Fiendish Retaliation and Fiendish Resistance.
The Great Old One - Mind Warp
When you reach 4th level, you can force a creature to see unknowable and horrifying sights when it harms you. When a creature hits you with a melee attack, you may use your reaction to Blind the creature until the start of its next turn or until it takes damage.
Wizard
Abjuration - Improved Ward
When you reach 4th level, your arcane ward continues to improve. When you create your magical ward, it has hit points equal to three times your wizard level + your Intelligence modifier. Whenever you cast an abjuration spell of 1st level or higher, the ward regains a number of hit points equal to three times the level of the spell.
Conjuration - Instinctive Jump
When you reach 4th level, you react to danger by teleporting to safety temporarily. When a creature moves within 5 feet of you, you may use your reaction to teleport to a location you can see within 30 feet. At the end of the turn, you return to the space that you vanished from, if it is unoccupied, or the nearest unoccupied space (chosen at random if more than one space is equally near.
Divination - See Failure
When you reach 4th level, you gain the ability to influence events by seeing a negative future. When a creature you can see makes a Saving Throw against a spell you did not cast, you can use your reaction to impose disadvantage on their saving throw. You can use this feature a number of times equal to your Intelligence modifier (minimum of 1). When you finish a long rest, you regain all expended uses.
Enchantment - Potent Charm
When you reach 4th level, your enchantment spells bypass some natural resistances of certain creatures. If a creature would normally have advantage on saving throws against being charmed, it does not benefit from that feature when resisting your spells.
Evocation - Elemental Defenses
When you reach 4th level, your knowledge of the elements give you an edge up aginst those that use the elemental magics. When you take Acid, Cold, Fire, Lightning, Poison, or Thunder damage, you may use your reaction to gain resistance against that damage type until the start of your next turn.
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Illusion - Question Reality
When you reach 4th level, you can harm those who touch your illusions as they doubt their existence.
When a creature touches an illusion you've created, you may use your reaction to force them to make an Intelligence saving throw. On a failure, they take psychic damage equal to your wizard level.
When a creature fails a check to see through an illusion you've created, you may use your reaction to deal psychic damage to them equal to your wizard level.
Necromancy - Shift Pain
When you reach 4th level, you can relocate some of the damage you take to your minions. When you take damage, you may use your reaction to have a willing creature within 30 feet take that damage instead, reduced by half your wizard level, rounded up.
Transmutation - Swap Elements
When you reach 4th level, you learn how to change the elements instinctively. When a creature other than you casts a spell that deals Acid, Cold, Fire, Lightning, Poison, or Thunder damage, you may use your reaction to change one of those damage types from that spell to another from that list. For example, you could change fireball to deal cold damage instead of fire, or have meteor swarm deal lightning and bludgeoning damage instead of fire and bludgeoning.
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Reactions or Replacements - DMG
Cleric
Death Domain - Bring to Death
When you reach 4th level, you feast on the death of your enemies. When a creature within 30 feet of you falls unconscious or dies, you may use your reaction to deal necrotic damage equal to half your cleric level to all creatures within 5 feet of that creature, including the triggering creature.
Paladin
Oathbreaker - Fight for Me
When you reach 4th level, your lack of oath displays itself in a different way than other Paladins, letting others do the work for you. When a creature within 10 feet of you expends their reaction, you may use your reaction to give them their reaction back. They can't use reactions until the end of the turn.
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