What Does Armour and Armour Class Do? – Baldur’s Gate 3

An important part of character customization and combat is the armour class on certain wearable items (Gloves, Boots, Armour). However, if you’re not familiar with the system, it can be quite confusing with how it works and what the numbers actually mean in combat. Fortuitously, we’re going to explain each of these systems, making sure you’re armoured up to take on the Forgotten Realm’s toughest fights.


In Baldur’s Gate 3, a character’s equipped armour piece (and sometimes gloves, boots, skills, or spells) provides the character with armour, which will generally increase their armour class (AC). When that character is attacked, the attacking roll has to be the same as or higher than their AC for it to hit them and do damage. This is the reason it can paradoxically feel like it is harder to hit bulkier targets, because they usually have a higher AC.

baldurs gate 3 armour guide gales armour class
Gale’s AC could be better”¦

There are three types of armour: light, medium, and heavy. The way that they are balanced is that the lighter the armour is, the more a character can increase their armour class with their dexterity modifier. Any Ability like Dexterity has a modifier, and it is calculated by subtracting it by ten, then dividing it by 2 (rounding down). Check out this table to see what your dexterity modifier is:

Dexterity Stat
Dexterity Modifier
1
-5
2-3
-4
4-5
-3
6-7
-2
8-9
-1
10-11
0
12-13
+1
14-15
+2
16-17
+3
18-19
+4
20
+5

Depending on the armour type your character is wearing, your AC may or may not benefit from the Dexterity bonus:

  • Light armor – Full AC Bonus from Dexterity
  • Medium armour – Maximum +2 AC from Dexterity
  • Heavy armour – No AC bonus from Dexterity

Some might think that’s not too bad of a trade-off; heavy armour does get all the way up to 18 AC, after all. However, this isn’t the only draw back to using heavier armours. The heavier an armour, the more likely that it imparts disadvantages on stealth rolls. Furthermore, it weighs more, making characters more likely to become encumbered.

baldurs gate 3 armour guide heavy armor example
How am I supposed to pass a stealth check in this?

Well, I can just give my sorcerer some heavy armour since they don’t have high dexterity, right? Unfortunately, it’s not that simple. Each class (and several races) come with proficiencies for certain armour types. When a certain character tries to wear an armour type that they’re not proficient in, they receive hefty penalties. For one, they won’t be able to cast spells. They also will be disadvantaged while making strength or dexterity rolls, and any saving throws or attack rolls.

Take a look at each of the classes and races to see what armour proficiencies they automatically have:

Class
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Race
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Now that you know where the armour proficiencies normally come from, it’s worth mentioning that there are other ways of making a character proficient in more armour types. Examples would be selecting a feat (like Heavily Armored) during a level up, or multi-classing. However, from multiclassing, you have to start out at level 1 with the class that has the desired armour proficiency, then switch to the other class.

You will notice on the table above that monks, sorcerers, and wizards don’t have proficiency in armour types – that doesn’t mean they don’t have ways to increase their armour class. Take monks for example, they have the intrinsic feature Unarmoured Defence, which adds their wisdom modifier on top of their base armour class. If that wasn’t good enough, they also receive actions and reactions, like Deflect Missiles, to further improve their defense.

The magic users have another tactic, the level 1 spell, Mage Armour. This increases the caster’s AC to 13 + their dexterity modifier, and it lasts until a long rest! That means that you only have to cast it once, then remember to cast it again after taking a long rest at camp. We would be remiss to not mention the king of AC spells, Mirror Image. This spell creates illusions next to the caster, and each one increases the caster’s AC by +3.

Now that we’re familiar with and understand Armour and AC, you probably want to optimize your characters! The most go-to way, besides equipping light, medium, or heavy armour, is equipping a shield on characters that are proficient. All shields (regardless of material) give a character +2 to AC, and just like with armour, shield proficiency is accessible through classes, races, and feats. Likewise, you can also invest in more AC by choosing the Defensive Duelist feat, which allows you to use a reaction to add to your AC.

Lastly, we want to touch on some items that give characters a bump in AC. A potion of speed will not only allow you to attack more, but also provide +2 AC. Items that always seem to be forgotten are scrolls; if you have any that are for the spell Mirror Image or Mage Armour, you can provide any character with a large AC boost for a fight!

baldurs gate 3 armour guide potion of speed

Hopefully this helped clear up some confusing aspects of the Armour Class system. Do you have any unique builds that give your character a ton of AC? Tell us about it in a comment!

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Kelson H.
Kelson H.

Kelson is a spud head from out west. He is most happy when holding a milky tea with too much honey and playing a sprawling role playing game or reading a fantasy novel. His video game tastes vary but his main genres are looter shooters, RPGs, and real time strategy games.

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