BG3 Action Economy Guide — Actions, Bonus Actions, Reactions Explained

Action Economy at a Glance

Actions — Your Primary Combat Resource

Actions are the most powerful turn resource in BG3. Every character gets exactly one Action per turn. Most combat abilities consume Actions: the Attack action (which may give multiple weapon attacks at higher levels), any spell of 1st level or higher that has a casting time of one action, and class-specific abilities like the Rogue's Cunning Action (which repurposes the Action into a Bonus Action for Dash, Disengage, or Hide).

The Attack action is deceptively flexible. Fighters, Rangers, and Paladins gain Extra Attack at level 5, meaning one Attack action resolves two weapon strikes. At Fighter level 11, you gain a third attack. This makes the Attack action extremely efficient for martial classes — far more valuable than a single-target damage spell of the same level for them.

Spellcasters use their Action to cast leveled spells. A Fireball costs an Action and a 3rd-level slot. Misty Step costs a Bonus Action and a 2nd-level slot — this type of slot-saving is a major reason some spells are considered better or worse than their spell-level equivalent. When evaluating a spell, always check whether it costs an Action or a Bonus Action.

Bonus Actions — The Most Contested Resource

You only ever get one Bonus Action per turn regardless of how many abilities say 'costs a Bonus Action.' This creates constant tension: a Rogue wants to use their Bonus Action for Cunning Action (Hide or Disengage); a Ranger wants it for Hunter's Mark repositioning; a Paladin wants Healing Word. You can only do one. The Bonus Action is arguably the tightest resource in BG3 combat.

Several game-changing abilities are deliberately placed on the Bonus Action to prevent them from dominating: Healing Word (vs. Cure Wounds on Action), Misty Step, Shove (after Tavern Brawler feat), and the Rogue's entire off-turn kit. The design intent is that using a Bonus Action should always feel like a meaningful choice, not a freebie.

Classes and builds that convert Actions into Bonus Actions — or that generate bonus Bonus Action sources — are extremely powerful. The Cunning Action (Rogue 3) giving a free Dash/Disengage as a Bonus Action is one of the most impactful class features in the game. Similarly, the Haste spell (concentration) grants an additional Action each turn, effectively doubling your throughput at the cost of concentration.

Best Bonus Action Abilities by Class

• Rogue (Cunning Action): Dash, Disengage, or Hide as a Bonus Action — exceptional mobility and survivability.
• Cleric / Bard: Healing Word heals as a Bonus Action instead of using your precious Action; always prefer it over Cure Wounds.
• Monk (Martial Arts): Make an unarmed strike as a Bonus Action after any unarmed or monk weapon attack — free extra hit.
• Barbarian: Reckless Attack grants Advantage on all attacks but lets enemies Advantage against you — toggle it as needed.
• Ranger (Hunter's Mark): Move the Mark to a new target as a Bonus Action when a marked target dies — keep damage flowing.
• Paladin (Healing Word via dip): A single Cleric level gives Healing Word access, making Paladin an outstanding off-healer.
• Fighter (Second Wind): Regain 1d10 + Fighter level HP as a Bonus Action on a short rest — excellent sustain tool.
• Thief Rogue (Fast Hands): Gains a second Bonus Action — making Thief the most Bonus-Action-efficient subclass in the game.

Reactions — Your Interrupt Window

Reactions trigger in response to events — usually your enemies' turns. You get exactly one Reaction per round. BG3 offers two reaction modes: Automatic (the reaction fires immediately when its trigger condition is met) and Ask (the game pauses and asks whether you want to use your reaction). For most players, Ask mode is strongly recommended because burning your reaction on a trivial Opportunity Attack wastes it against a much more important trigger later.

The Shield spell is one of the best reaction uses in BG3. When hit, a Wizard or Sorcerer can cast Shield as a reaction using a 1st-level slot to gain +5 AC until the start of their next turn — often turning the hit into a miss retroactively. Similarly, Counterspell lets you cancel an enemy spell as a reaction with a 3rd-level slot, shutting down dangerous encounters entirely.

Opportunity Attacks are the default reaction most characters use: when an enemy leaves your melee range without Disengaging, you swing at them. This is less powerful than Shield or Counterspell but still very useful for punishing enemies who try to reach your backline. Classes with powerful reaction abilities should carefully evaluate whether taking an Opportunity Attack is worth sacrificing their Shield or Counterspell potential.

Action vs Bonus Action Spell Comparison

Verdict: Bonus Action spells are always premium because they leave your Action free. If a spell has both an Action and Bonus Action version, strongly prefer the Bonus Action version.

Action Economy Tips by Role