In one 6-second round, a character or creature may perform one Movement, one Action and one Bonus Action during a turn. Once per round between others’ turns, a character or creature may perform one Reaction. Legendary Actions may also be done between others’ turns in a round. (Special abilities and conditions may affect these options.)
In my campaigns, I typically add two house rules that break the official RAW (rules as written) action economy:
* Bonus Actions As Actions: Instead of one Action and one Bonus Action, a character may perform two Bonus Actions in the same turn. Spellcasting limitations still apply (only one cantrip and one leveled spell per turn, or two cantrips). Movement and Reactions are not affected.
* Delay (Reaction): Wait and change your Initiative order in the round to a lower-ranked turn. The new position in the order remains until the end of the encounter or when a new Initiative order is made. (Typically this delay is done to better coordinate with allied characters in the same round, such as waiting to attack until after a buff is given Some DMs may already be playing the Ready action like this rule, but RAW it does not work that way in 5e.)
* Move (Normal Terrain): 5 feet distance per 5 feet movement.
* Move (Difficult Terrain): 5 feet distance per 10 feet movement.
* Move (While In Grapple): Speed halved this turn unless target two sizes smaller.
* Climb: 5 feet distance per 10 feet movement.
* Swim: 5 feet distance per 10 feet movement.
* Drop Prone: No cost in movement.
* Crawl: 5 feet distance per 10 feet movement.
* Squeeze Through Opening/Passage: 5 feet distance per 10 feet movement.
* Stand Up: Costs half movement speed that turn.
* Mount Or Dismount: Costs half movement speed that turn.
* High Jump: 5 feet height per 5 feet movement.
* Long Jump: 5 feet distance per 10 feet movement.
* Dash (as an Action): Double movement speed in turn.
* Grappled Condition: A grappled creature’s speed becomes 0, and it can’t benefit from any bonus to its speed. The condition ends if the grappler is incapacitated (see the condition). The condition also ends if an effect removes the grappled creature from the reach of the grappler or grappling effect, such as when a creature is hurled away by the Thunderwave spell.
* Restrained Condition: A restrained creature’s speed becomes 0, and it can’t benefit from any bonus to its speed.
* Mobile (Feat): If doing Dash action, difficult terrain does not hinder.
* Land’s Stride (Ranger Level 8+): Nonmagical difficult terrain no hindrance.
* Second-Story Work (Rogue Thief Level 3+): Climb at full movement speed.
* Longstrider (spell level 2): Increase movement by 10 feet.
* Haste (spell level 3): Movement speed is doubled, plus additional Action per turn.
* Freedom Of Movement (spell level 4): Difficult terrain or underwater cause no hindrance, also escape restraints for 5 feet of movement speed.
* Boots Of Speed: Movement speed (walking) is doubled. Bonus Action to activate, lasts 10 minutes before needing recharge.
* Attack (Normal): Make one melee or ranged attack with a weapon or unarmed. (Accounts for multiple minor feints, strikes, parries, blocks and dodges throughout the round.)
* Attack (Extra Attack): Make two or more attacks on one or more targets.
* Attack (Multiattack): Make two or more attacks on one or more targets.
* Attack (Loading Weapon): Make one attack with weapon per round, regardless of extra attack abilities. (Accounts for reloading time during the round.)
* Attack (Grapple): Contest of Strength (Athletics) vs. target’s Strength (Athletics) or Dexterity (Acrobatics).
* Attack (Shove): Replace one attack roll with a contest of Strength (Athletics) vs. target’s Strength (Athletics) or Dexterity (Acrobatics); if attack succeeds, target either knocked Prone or pushed 5 feet in any direction.
* Cast A Spell: If components met, use a spell with a one action casting time if no other (non-cantrip) spell has already been used as an Action or Bonus Action.
* Dash: Double movement speed in turn. (Accounts for running or sprinting during turn.)
* Disengage: No opportunity attacks against you while Moving. (Accounts for “controlled rout” or “guarded retreat.”)
* Dodge: Attack rolls targeting you suffer Disadvantage until your next turn. (Accounts for “defensive fighting” or “focused blocks and parries” in combat.)
* Equip Or Unequip Shield: Fix straps to pick up or drop a shield.
* Escape: Use either Strength (Athletics) or Dexterity (Acrobatics) vs. grappler’s Strength (Athletics) to end grapple.
* Help: Grant an ally Advantage on one attack or ability check roll.
* Hide: Make Dexterity (Stealth) check if movement unobserved.
* Interact With Multiple Object: One object is a free action, several may take a full Action (DM’s judgment).
* Read A Magic Scroll: Ignore casting time of spell effect, use takes 1 Action. (DMG, p. 139)
* Ready: Name conditions for one Action to happen as a Reaction instead before next turn.
* Retrieve Item: Get one piece of equipment out of a backpack or Bag of Holding.
* Search (Own Space): Find hidden objects or secret doors within your space; DM may require ability check.
* Stabilize A Dying Creature: Make a DC 10 Wisdom (Medicine) check on target.
* Throw/Splash: Hurl liquid contents of a container at a creature or area.
* Use An Object: Typically complicated tool or magic item, such as when picking a lock.
* Use Ball Bearing Or Caltrops: Covers area to trip or injure creatures. (PHB, p. 151)
* Use Healer’s Kit: Automatically stabilizes dying creature.
* Use Hunting Trap: Set saw-toothed steel ring open.
* Use Poison: Apply toxin to melee weapon or ammunition.
* Use A Potion: Either drink for yourself or administer to another. (DMG, p. 139)
* Use Tinderbox: Ignite a torch, lamp, oil, dry campfire or similar flammable fuel.
* Controlling A Mount: May only take the Dash, Disengage or Dodge action on its own.
* Incapacitated, Paralyzed, Petrified, Stunned Or Unconscious Conditions: Any creature suffering one of these conditions can’t take actions or reactions.
* Dual Wielder (Feat): Fight two-handed even when one weapon is not Light.
* Healer (Feat): Use healing kit to restore 1d6+4 hit points.
* Use Breath Weapon (Dragonborn): Targets make Constitution saving throws for half damage.
* Countercharm (Bard Level 6+): Give allies Advantage vs. mind-influencing effects.
* Channel Divinity: Turn Undead (Cleric Level 2+): Repel undead creatures.
* Divine Intervention (Cleric Level 10+): Implore a deity for immediate aid.
* Wild Shape (Druid Level 2+): Transform into a beast or other special creature.
* Action Surge (Fighter Level 2+): Take an additional Action during your turn.
* Stillness Of Mind (Monk Level 7+): End charmed or frightened condition on yourself.
* Divine Sense (Paladin Level 1+): Sense certain creatures within 60 feet.
* Lay On Hands (Paladin Level 1+): Heal hit points with a touch.
* Primeval Awareness (Ranger Level 3+): Sense special creatures within miles.
* Pact Of The Chain (Warlock Level 3+): When using Attack action, allow familiar to make one attack in place of your own.
* Pact Of The Blade (Warlock Level 3+): Create a pact weapon in your empty hand.
* Haste (spell level 3): Additional Action per turn, plus Movement speed is doubled.
Reminder On Extra Attacks…
* Off-Hand Attack (Bonus Action): Requires Light melee weapon unless noted otherwise.
* Barbarian Level 5+: 2 attacks per Attack Action.
* Bard (College of Valor) Level 6+: 2 attacks per Attack Action.
* Cleric (War Domain) Level 1+: Extra attack in Attack action as Bonus Action.
* Fighter Level 5-10: 2 attacks per Attack Action.
* Fighter Level 11-19: 3 attacks per Attack Action.
* Fighter Level 20: 4 attacks per Attack Action.
* Monk Level 1+: Extra unarmed/monk weapon attack in Attack action as Bonus Action.
* Monk Level 2+: +2 extra unarmed attacks as Bonus Action per Ki point spent.
* Monk Level 5+: 2 attacks per Attack Action using any weapon.
* Paladin Level 5+: 2 attacks per Attack Action.
* Ranger Level 5+: 2 attacks per Attack Action.
STANDARD BONUS ACTIONS
* Off-Hand Attack: When doing Attack as a main Action, add one Attack using a Light weapon held in the other hand.
* Cast A Spell: If components met, use a spell with one bonus action casting time if no other (non-cantrip) spell has already been used as an Action or Bonus Action. (Spells of this type are often tied to Movement or an Action such as Attack.)
Special Bonus Actions…
* Charger (Feat): If doing Dash action, make one melee weapon attack or shove at end of move; additional bonus if charging at least 10 feet in straight line.
* Crossbow Expert (Feat): If doing one-handed Attack action, shoot hand crossbow with other hand.
* Polearm Master (Feat): If Attack action with glaive, halberd, or quarterstaff, make attack with opposite end of weapon (1d4 bludgeoning damage). Also, gain opportunity attack when targets enter reach.
* Shield Master (Feat): If Attack action, use shield to make a shove attack as bonus action. Also, use reaction to turn Dexterity save for half damage into no damage.
* Tavern Brawler (Feat): If Attack (unarmed or improvised weapon) hits, may attempt a grapple as bonus action.
* Enter A Rage (Barbarian Level 1+): Gain various bonuses while in this state.
* Use Bardic Inspiration (Bard Level 1+): Give others bonus dice to use on their turns.
* War Priest Attack (Cleric, War Domain Level 1+): One extra attack in Attack Action.
* Combat Wild Shape (Druid, Circle of the Moon, Level 2+): Transform into a beast.
* Second Wind (Fighter Level 1+): Regain 1d10 + Fighter Level hit points.
* Martial Arts (Monk Level 1+): Unarmed strike or monk weapon attack during Attack Action.
* Vanish (Ranger Level 14+): Use Hide as a Bonus Action.
* Cunning Action (Rogue Level 2+): Use Dash, Disengage or Hide as Bonus Action.
* Fast Hands (Rogue Thief level 3+): Use Dexterity (Sleight of Hand) as Bonus Action.
* Cast Quickened Spell (Sorcerer Level 3+ Metamagic): Use 2 sorcery points to cast a spell with 1 Action casting time as Bonus Action if no other (non-cantrip) spell has already been used as an Action.
* Incapacitated, Paralyzed, Petrified, Stunned Or Unconscious Conditions: Any creature suffering one of these conditions can’t take actions or reactions.
* Expeditious Retreat (spell level 1): Dash as a Bonus Action.
* Activate Boots of Speed, Dancing Sword, Decanter of Endless Water, Flame Tongue blade, Glamoured Studded Leather armor or Sun Blade; or send messages via a Helm of Telepathy, cast a spell from a Necklace of Prayer Beads, exhale flames by Potion of Fire Breath, switch effects on a Rod of Lordly Might, attack with a Scimitar of Speed, or various other magical item features noted as Bonus Actions.
* Cast A Spell: If components met, use a spell with a reaction casting time. (Feather Fall, Hellish Rebuke, Shield and Counterspell are reaction spells.)
* End Concentration On A Spell: Effect stops immediately. (Spell effects that do not have concentration cannot be ended before their duration unless using a Dispel Magic spell.)
* Opportunity Attack: Make one melee weapon attack roll on one target moving out of your weapon reach; does not count if target is changing spaces within reach. Extra attack or multiattack does not grant more than one opportunity attack. Teleportation and forced movement do not provoke opportunity attacks.
* Dismount: Land on feet if mount is knocked Prone.
* Use Readied Action: When doing Ready as main Action, resolve Action when conditions are triggered.
* Defensive Duelist (Feat): Finesse weapon proficiency bonus added to AC vs. melee attack.
* Mage Slayer (Feat): Make melee weapon attack against spellcaster casting a spell within 5 feet.
* Polearm Master (Feat): gain opportunity attack when targets enter reach. Also, if Attack action with glaive, halberd, or quarterstaff, make attack with opposite end of weapon (1d4 bludgeoning damage).
* Sentinel (Feat): Hit with opportunity attack drops target’s speed to 0. Disengage does not stop your opportunity attacks. Enemies within 5 feet who attack other targets can be attacked with melee weapon.
* Shield Master (Feat): use reaction to turn Dexterity save for half damage into no damage.. Also, if Attack action, use shield to make a shove attack as bonus action.
* War Caster (Feat): If opportunity attack provoked near you, may cast at the target a spell of 1 action casting time as a reaction.
* Uncanny Dodge (Rogue Level 5+): Half damage from attacks you can see.
* DM will rule if described action is an Action, Bonus Action or Free Action.
* DM will rule if an ability check is also required to perform the improvised action.
FREE ACTIONS (typically instant results)
* Interact With An Object: Minor additions to other Movement or Action (draw a sword in Attack action, reload a crossbow, open a chest, open a door in a Movement).
* Communication: Talking among characters during a round up to DM’s judgment. Charisma ability check might also be required. Player role-playing determines if NPC is Friendly, Indifferent or Hostile.
* Make A Concentration Check: When taking damage, spellcaster must make a Constitution saving throw DC 10 or half damage (whichever higher), failure end concentration spell effect.
* Make A Death Saving Throw: Roll 1d20; see PHB p. 197.
* Make A Saving Throw: Made in response to sudden hazards or spell effects.
* Use A Passive Ability Check: DM uses ability to measure sharing automatic results or knowledge. Passive scores add 10 to a character’s ability check modifier.
* Use Bardic Inspiration: Add one Inspiration die to a roll if given within the past 10 minutes.
Special free actions…
* Dungeon Delver (Feat): Search for traps while moving at normal speed.
* Lucky (Feat): Spend one luck point to roll additional d20.
* Relentless Endurance (Half-Orc Trait): At 0 hit points, drop to 1 h.p. instead.
* Stonecunning (Dwarf Trait): Intelligence (History) to recognize origin of stonework.
* Use Metamagic (Sorcerer Level 3+): Add effects to spells when casting.
* Contingent Spells: Any spell effects set up by the 6th-level Contingency spell.
Powerful creatures may make a certain number of additional actions at the end of other characters’ and creatures; turns in the Initiative order. Some options may count as multiple legendary actions in the same round. Some examples:
* Aboleth: Detect, tail swipe or psychic drain.
* Adult Dragon: Detect, tail attack or wing attack.
* Beholder: Use one random eye ray.
* Demilich: Flight, cloud of dust, energy drain or vile curse.
* Empyrean: Attack, bolster or trembling strike.
* Kraken: Tentacle attack, fling, lightning storm, ink cloud.
* Lich: Cast cantrip, paralyzing touch, frightening gaze or disrupt life.
* Mummy Lord: Attack, blinding dust, blasphemous word, channel negative energy or whirlwind of sand.
* Solar Angel: Teleport, searing burst or blinding gaze.
* Tarrasque: Attack (claw or tail), move or chomp (bite attack).
* Unicorn: Hooves, shimmering shield or heal self.
* Vampire: Move, unarmed strike or bite.
THINGS THAT TAKE LONGER THAN ONE ROUND
* Casting A Spell: As per casting time listed per spell. (Examples include Mending, Prayer of Healing, Animate Dead, Conjure Elemental and Raise Dead.)
* Casting A Ritual Spell: Takes 10 minutes longer than normal casting time.
* Put On Or Take Off Light Armor: 1 minute.
* Put On Medium Armor: 5 minutes.
* Put On Heavy Armor: 10 minutes.
* Take Off Medium Armor: 1 minute.
* Take Off Heavy Armor: 5 minutes.
* Searching A Room: 1 minute with Disadvantage, 5 minutes normal check, 10 minutes with Advantage, 1 hour for automatic success.
* Inspiring Leader (Feat): Spend 10 minutes to give six allies level + Charisma modifier in temporary hit points.
* Natural Explorer (Ranger Level 1+): Special senses after an hour in favored terrain.
* Hide In Plain Sight (Ranger Level 10+): Create camouflage for yourself.
THINGS THAT TAKE A SHORT REST (1 HOUR)
* Spend Hit Dice: Roll to recover lost hit points.
* Use Song Of Rest (Bard Level 2+): Allies heal extra hit points during short rest.
* Font Of Inspiration (Bard Level 5+): Regain uses of Bardic Inspiration.
* Natural Recovery (Druid, Circle of the Land, Level 2+): Regain half druid level in spell slots.
* Pact Of The Tomb (Warlock Level 3+): Create a new Book of Shadows.
* Arcane Recovery (Wizard Level 1+): Regain half wizard level in spell slots.
THINGS THAT TAKE A LONG REST (8 HOURS)
* Hit Point Recovery: All h.p. reset back to maximum number.
* Hit Dice Recovery: Half of Hit Dice spent during Short Rests recovered.
* Spell Slot Recovery: All spent spell slots reset.
* Exhaustion Recovery: One level of Exhaustion removed.
OTHER LONG ACTIONS
* Copy Spell Into Spellbook (Wizard Level 1+): 2 hours (and 50 g.p.) per level of spell. (For most specialist wizards, half time and cost for spells in their school.)