BG3 Armor Class Guide

While exploring and questing are key parts of Baldur’s Gate 3, even if you try to tread a path of peace, you’re going to end up in some battles. BG3 has my favorite kind of combat, which is turn-based and tactical rather than full-on action. This means that understanding how the algorithms behind the scenes work is key to success, and one of the most important ones here is Armor Class. It’s taken straight from Dungeons & Dragons, but if you’re not familiar with it, read on for our full Armour Class guide.

How to calculate your AC in Baldur’s Gate 3

Many characters, in most situations, will derive their Armor Class (AC) from their armor, adding a shield if they're using one in their offhand, plus any bonuses (such as Dexterity or magic items). It is also possible to have spells and effects set your base AC. Those with a distant Dungeons & Dragons past can forget all they know about THAC0, as wanting a low AC is a thing of the past in D&D 5e, which Baldu’rs Gate 3 is based on. In BG3, a high AC number is better than a low one.

Related: BG3 Illithid Powers Guide

Non-magical light armor (such as Padded and Leather) gives a base AC of around 11-12, medium armor (Hide and Chain Shirt) 12-13, and heavy armor (Chainmail, Ring Mail) 14-16. There is some crossover when you start to find better quality items, while Plate is the best (heavy) armor with a non-magical base AC of 18. If you’re only wearing clothes, your base AC is 10.

If you also carry a shield, you will usually get an AC bonus of +2. Magical armor can then give further bonuses. For example, if you had +2 Magic Plate and a +1 Magic Shield, your ACC from these items would be 23 (18+2 then adding the shield+2+1). For a list of all armor ACs, see the table below.

Basic Armor (AC) table

How does Dexterity affect Armor Class?

While classes such as bards and rogues will tend to wear light armor or non at all, and many other classes will stick to medium, the lower AC given by the armor itself is bolstered instead by being more flexible. Lighter armor users can benefit from an AC bonus based on their Dexterity.

• Light armor: Full Dexterity bonus added to AC (+5 for a Dexterity of 20, right up to +10 if you somehow get to 30 Dex)
• Medium armor: Maximum Dexterity bonus of +2.

All heavy armors, and many medium armors, have the added disadvantage of not allowing the character to use Stealth. 

Helmets and AC

Helmets do not directly affect AC in Baldur’s Gate 3 despite following the same rules of armor proficiency. However, they are still important items to equip as soon as you find some, as they give your characters important bonuses. 

• Light: You gain a bonus to Dexterity saving throws.
• Medium and Heavy: The enemy cannot hit you with a Critical Hit.

You may find other types of helmets, including magic ones, but these are the standard types you’ll find throughout the game.

How important is Armor Class in BG3?

Having a high AC doesn’t mean you’ll take any less damage per hit, but it does mean you’re less likely to be hit at all, which is clearly a good thing. If an attack role is the same as your AC rating or higher, you’ve been hit. Damage is then rolled and taken off of your current Hit Point (HP) total. Remember that even if you have a monumental AC, you’ll still be hit if the enemy rolls a natural 20. And you know that is going to happen just when you don’t want it to!

All Baldur's Gate 3 Armor Proficiencies by Class

If you’re about to build a character it is important to remember that not all classes are proficient in all armor types. Wearing armor (or a shield) if you’re not proficient in it comes with a series of penalties that make it borderline impossible to make it work. For example, you will not be able to cast spells, and you’ll always have the Disadvantage status in combat.

• None: Monk, Sorcerer, Wizard
• Light only: Bard, Rogue, Warlock
• Light, Medium, and Shields: Barbarian, Cleric, Ranger
• Light, Medium, and Shields (only non-metallic): Druid
• Light, Medium, and Shields: Fighter, Paladin

Related: Best Concentration Spells in BG3

While it is possible to gain extra armor proficiencies in a variety of ways (such as multiclassing and feats), this often comes at the expense of better options, and I wouldn’t advise it.

Other ways to improve your AC

There are also some spells and effects that can increase your AC. Some examples include:

• Armor of Shadows (spell): +3 AC if you’re not wearing armor.
• Shield of Faith (spell): +2 AC.
• Defense (fighting style): +1 AC (martial classes only).
• Fighting Initiate (feat): Non-martial classes can use this feat to gain the Defense fighting style (above), gaining +1 AC.

There are also occasional improvements that improve elements of your AC:

• Defensive Duelist (feat): +2 AC as a reaction in melee, as long as you’re wielding a Finesse weapon.
• Mirror Image (spell): This creates three mirror images of the character. These are defeated by one hit, but while active, each gives the recipient +3 AC.

For more Baldur's Gate 3 guides here at Pro Game Guides, click through to Best Sorcerer Metamagic in BG3 and BG3 Wizard Build Guide – Best Stats and Subclass and loads more!