I play Baldur’s Gate 3 a lot, and I want to strip Armor Class down to what actually matters. AC decides whether an enemy hits you or not. You either take full damage or nothing — that rule alone should change how you build characters. I’ve noticed players treat AC like a number to chase, instead of understanding why each point helps.
Basics: what AC does
When an enemy attacks, they roll a d20 and add modifiers. If that total meets or beats your AC, you get hit. Simple. Higher AC = fewer hits. Honestly, that can be all the difference in fights with dozens of enemies.
Why focus on AC? Because avoiding damage is often better than shrugging it off with healing. This doesn’t always work — some enemies use saves or high attack bonuses that punch through you anyway. Depends on your niche.
How to calculate AC (short)
// Typical formulas you'll use
No armor: 10 + DEX mod
Light armor: Armor base + DEX mod
Medium armor: Armor base + min(DEX mod, +2)
Heavy armor: Armor base only
Shield: +2 (stackable)Quick question: do you need a shield? If you can use one, yes — most of the time it’s free AC. By the way, some classes have Unarmored Defense that swaps in WIS or CON instead of armor. Use it when it gives more than wearing armor.
| Armor type | How AC is figured |
|---|---|
| No armor | 10 + DEX mod (Monk/Barbarian may use other stats) |
| Light | Armor base + DEX mod |
| Medium | Armor base + DEX mod (capped at +2) |
| Heavy | Armor base only |
Class choices and practical tips
A heavy-armored Fighter can reach good AC early. Rogues and Rangers get high AC through Dex and light armor while staying mobile. Monks and Barbarians often outpace armor when you pump the right stats. I’ve found a Monk with Bracers of Defense and high WIS can surprise you — counterintuitive, right?
- Fighters/Paladins: wear heavy armor, add shield; you’ll hit reliable AC numbers fast.
- Rogues/Bards: prioritize Dexterity and studded leather; mobility matters more than raw armor.
- Monks/Barbarians: check Unarmored Defense formulas before putting on armor (save that proficiency!).
There are exceptions. Some builds want a magical robe that grants AC or unique effects, so don’t tunnel-vision on physical armor.
Magical items and combos
Items can push AC past what armor alone gives. Common pieces (rings, cloaks, bracers) often add +1 or +2 and stack with other bonuses. Combine things that work together — synergy beats a single huge item more often than you’d think.
“If you can get +2 from bracers and still use your Unarmored Defense, you just bought yourself several level’s worth of survivability.” — practical note
Power combo example: Bracers of Defense + Monk Unarmored Defense + decent DEX/WIS can reach 18–20 AC by mid to late game. Try it. (Yes, it’s allowed.)
What stacks and common mistakes
Base AC calculation is exclusive — you pick the method. Most other bonuses stack: shields, magic item bonuses, certain spells. Don’t wear armor that cancels your class feature, and please equip a shield if you have proficiency and need the extra defense.
- Don’t mix Mage Armor with actual armor — the game won’t give you both.
- Don’t ignore Dex on medium armor builds — you’re often leaving +2 AC on the table.
- Using two-handed weapons when you need a shield? That’s a play, but it’s risky.
Also: some enemies use spells or effects that bypass AC via saves. That’s why I balance AC with hit points and saves. You need all three.
Specific advice I give players
- Want tankiness fast? Take one level of Fighter for armor profs — it’s a small cost for big gains.
- Max Dex for light-armor stealth builds — better AC and initiative.
- Check item synergies before swapping gear; sometimes a weaker-looking item offers a unique stacking bonus.
Here’s the funny part: players will chase Plate with full faith, but a finely tuned Dex build can be just as hard to hit and a lot more useful in stealth and movement. Controversial? Maybe. But I’ve seen it work in multiple runs.
Small checklist (copy this)
- Pick the right AC formula for your class.
- Equip shield if proficient and it helps your role.
- Compare Unarmored Defense vs. armor — do the math.
- Look for item synergies, not just big numbers.
To be fair, some fights still hinge on luck — long rolls and bad crits exist. Watch this: good positioning and crowd control often save more HP than one extra point of AC. So plan your defense around encounters, not only gear.
// Example: Rogue with Studded Leather, DEX 18
Base studded leather = 12
DEX mod = +4
Final AC = 16Oddly enough, repetition helps learning — try the same build twice with small tweaks. You’ll notice what truly matters. Between us, I repeat setups until I stop being surprised.
One counterintuitive insight: increasing Constitution for more HP can be better than chasing a marginal AC gain from gear. More HP smooths out bad luck over many fights.
Final quick note: 2025 patch changes tightened some item drops and enemy attack bonuses; always check your current game stats before finalizing a build. There are exceptions, and things change with updates. Keep testing, and don’t be afraid to break a rule or two — that’s how you learn.
“AC is a sieve — some hits slip through, some don’t. Make the sieve as fine as you can, but fix the holes elsewhere too.”
Good luck out there. Don’t forget to laugh when a critical still ruins your plans — it happens, and yeah, it’s frustrating. 😅
