Baldur’s Gate 3 Combat Guide: Actions, Reactions, Advantage and Positioning

A good combat turn therefore asks four questions in order: who must be stopped before they act, where do I need to stand, which resource solves the problem, and what reaction do I need to keep available after my turn ends?

The initiative bar is a tactical plan, not just a list of portraits.

Initiative decides order, but adjacent allied portraits can share a turn-order position, letting you switch between those characters and interleave their actions. That is enormously useful: one character can create Wet, another can cast lightning, then the first can finish movement; a support can Bless before the martial spends attacks.

When an enemy acts between two party portraits, that sequencing window closes. Before the first action of the round, scan the initiative bar and identify which enemy turn you can remove.

The Action pays for most attacks and spells. Bonus Actions cover many class abilities, Jump, Shove, off-hand attacks and other quick tools. Movement is its own pool; spending movement does not consume the Action. Reactions are usually spent outside your turn when a trigger occurs.

Do not end turn while a useful Bonus Action or safe movement remains, but do not spend a resource merely because the icon is lit. A Bonus Action potion can be worth saving; a Reaction may need to remain available for Counterspell, Shield, Divine Smite prompts or an Opportunity Attack.

The Reactions menu lets you enable/disable reactions and, for many reactions, choose whether the game should ask before spending the resource. Ask is valuable whenever a reaction consumes a spell slot, superiority die or other limited resource.

A Paladin who auto-spends a weak Smite reaction on the first target may not have it for the critical target. A Wizard who burns the Reaction before an enemy caster acts cannot Counterspell. Reaction management is part of your turn even though the button is pressed later.

Use the Reactions panel to decide which effects trigger automatically and which should ask first.

Weapon and spell attacks generally roll against Armour Class. Advantage rolls two d20s and keeps the higher; Disadvantage keeps the lower. When both apply, they usually cancel. The displayed hit chance is the fastest diagnostic tool in the game.

If the number is bad, do not immediately press the same attack anyway. Move out of Threatened range, find high ground, create Advantage, use Bless, target a different defence, or switch to a spell that forces a saving throw instead of an attack roll.

Advantage changes the probability of an attack before damage is ever rolled.

At roughly 2.5 m of elevation difference, a higher attacker receives +2 to attack rolls; attacking from sufficiently lower ground takes -2. This applies to attack rolls broadly, not only bows. Sharpshooter removes the Low Ground penalty for proficient ranged weapon attacks.

High ground also changes sight lines and pathing, which is often more important than the +2. A ranged character on a balcony can force melee enemies to waste movement or Dash just to become relevant.

Elevation improves ranged pressure and can add the +2 High Ground attack bonus.

A Fireball does not care about the target's Armour Class; it asks for a Dexterity save. Hold Person attacks Wisdom. Many control spells therefore become dramatically better or worse depending on the enemy's saving-throw profile.

Examine enemies. If a heavily armoured target is difficult to hit but has poor Wisdom, a control spell may be the correct answer. If the target is resistant or immune to the condition, change plan before spending the slot.

A character can maintain only one concentration spell at a time. Casting a new concentration spell immediately ends the old one — particularly dangerous if the old spell was Haste, because breaking Haste can inflict Lethargic.

When a concentrating character takes damage, the concentration save DC is 10 or half the damage taken, whichever is higher. That is why armour, positioning, War Caster, Constitution save proficiency and simply killing nearby enemies all protect concentration.

The combat log can reveal Opportunity Attacks, damage and Concentration saving throws in the same exchange.

Leaving an enemy's melee reach can provoke an Opportunity Attack when that enemy has a Reaction and the relevant passive available. Sometimes taking that hit is worth it; sometimes Disengage, teleportation, forced movement or simply killing the enemy first is better.

You can also exploit enemy reactions. If a durable summon or frontliner safely triggers the Opportunity Attack, a fragile character may be free to leave later in the round.

BG3's environment is a combat system. Wet creates vulnerability to Cold and Lightning while granting Fire resistance. Grease and Ice can create Prone risks. Darkness changes sight lines. Fire surfaces punish stationary clusters.

The correct question is not ‘what is my strongest spell?’ but ‘what state can the party create, and who benefits from that state next?’

Wet/electrified surfaces are an example of party members building on the same battlefield state.

A dead enemy loses every future action. A half-dead enemy loses nothing. Prioritise enemies who act before your next safe window, enemy controllers/casters, creatures capable of deleting a vulnerable ally, and targets you can actually remove this round.

Boss tunnel vision is a trap when two dangerous adds are about to act. Conversely, clearing every low-value add is a trap when the boss will win a long fight. Read the initiative bar and decide which upcoming actions matter.

Ungrouping, hiding, using line of sight and entering from a different doorway are normal uses of the game's systems. You do not need to stack twenty barrels to benefit from pre-combat planning.

Place the ranged character where the first shot works, keep the concentration caster out of easy melee reach, and make sure the frontliner can reach the enemy without spending the entire first turn Dashing.

• How many actions do I get? Most characters begin with one Action, one Bonus Action, movement and one Reaction resource; features can add more.

• Does high ground give Advantage? No. Current BG3 uses a +2 attack bonus for high ground and -2 for low ground.

• Can I concentrate on two spells? No. A new concentration spell ends the old one.

• What is the concentration save DC? 10 or half the damage taken, whichever is higher.

• Should reactions be automatic? Cheap reactions can be; expensive resource-spending reactions are usually safer on Ask.