What Increases AC in D&D? A Comprehensive Guide
Armor Class (AC) in Dungeons & Dragons (D&D) represents how difficult a creature is to hit in combat. A higher AC makes a creature harder to strike successfully. Many factors influence AC, ranging from the armor a character wears to their natural agility and magical enhancements.
Core Components of AC Calculation
AC is determined by a combination of factors, with the most common starting point being the type of armor worn. Here’s a breakdown:
- Armor: Different types of armor offer varying levels of protection. Light armor allows you to add your Dexterity modifier to your AC, medium armor typically limits the Dexterity bonus you can add, and heavy armor often provides a fixed AC value, regardless of your Dexterity.
- Shields: Wielding a shield typically grants a bonus to your AC, usually +2.
- Dexterity Modifier: Dexterity plays a crucial role in determining AC, especially when wearing light or medium armor. A higher Dexterity score translates to a higher AC.
- Natural Armor: Some creatures, including certain monsters and characters with specific racial traits or class features, possess natural armor. This provides a base AC value that armor can then augment.
- Other Modifiers: Various spells, class features, feats, and magical items can further increase AC. These can provide bonuses to AC directly or indirectly by influencing Dexterity, providing temporary hit points (essentially delaying damage that would reduce hit points), or imposing disadvantage on enemy attack rolls.
Armor: Your First Line of Defense
The type of armor you wear significantly impacts your AC. Understanding the different types and their properties is crucial.
Light Armor
Light armor, such as padded armor, leather armor, and studded leather armor, allows you to add your full Dexterity modifier to your AC. This makes it ideal for characters with high Dexterity scores, like Rogues and Rangers.
Medium Armor
Medium armor, including hide armor, chain shirt, scale mail, and breastplate, allows you to add your Dexterity modifier, up to a maximum of +2, to your AC. This provides a balance between protection and agility.
Heavy Armor
Heavy armor, such as ring mail, chain mail, splint armor, and plate armor, provides a fixed AC value, irrespective of your Dexterity modifier. However, wearing heavy armor often imposes penalties, such as disadvantage on Stealth checks, and may require a certain Strength score to avoid reduced speed.
Shields: An Extra Layer of Protection
A shield provides a straightforward +2 bonus to AC. However, shields require one hand to wield, which can limit your options for weapon or spellcasting.
Dexterity: Agility and Evasion
Your Dexterity modifier is a key component of your AC, particularly when wearing light or medium armor. A higher Dexterity score means you are more agile and harder to hit.
Unarmored Defense
Some classes, like Barbarians and Monks, feature abilities called Unarmored Defense, which provide an alternative way to calculate AC when not wearing armor. These usually involve adding your Constitution or Wisdom modifier (respectively) to your AC alongside your Dexterity modifier.
Natural Armor: Born Tough
Certain creatures and characters have natural armor, which provides a base AC value. This might be due to thick hides, exoskeletons, or inherent magical protection.
Magic and Abilities: Beyond the Physical
Beyond armor and inherent attributes, magical spells and abilities can significantly enhance AC.
Spells
Spells like Shield, Mage Armor, and Barkskin can temporarily or permanently increase a creature’s AC.
Class Features
Various class features, such as a Paladin’s Defensive Fighting Style (+1 to AC when wearing armor) or a Fighter’s Dueling Fighting Style (which can improve AC indirectly by making you more effective in single combat and thus reducing the number of attacks against you), can also bolster AC.
Magical Items
Magical items, such as rings of protection and cloaks of protection, often grant bonuses to AC and saving throws.
Situational Modifiers
Certain situations can also impact AC, such as being prone (advantage on attack rolls against you within 5 feet, but disadvantage on ranged attacks against you) or having cover (providing a bonus to AC and Dexterity saving throws).
AC Calculation Rules
It’s important to understand the rules governing AC calculation. Here are some key points:
- Stacking: AC bonuses generally do not stack, unless explicitly stated. For example, you cannot add the AC bonuses from wearing armor and using Mage Armor. You would use the higher value.
- Multiple AC Calculations: If you have multiple ways to calculate your AC (e.g., wearing armor and using Unarmored Defense), you choose which one to use.
Frequently Asked Questions (FAQs)
1. Can I wear armor and use Unarmored Defense?
No, you cannot. Unarmored Defense abilities specify that they function only when you are not wearing armor. You must choose which method to use to calculate your AC.
2. Does the Shield spell stack with armor?
Yes, the Shield spell provides a +5 bonus to AC and explicitly states that it stacks with armor. It’s a reaction, used after you are targeted by an attack.
3. If I have a high Dexterity, should I always wear light armor?
Not necessarily. While light armor allows you to add your full Dexterity modifier, medium armor can sometimes provide higher AC if it has a higher base value and you have a Dexterity modifier of +2 or less. Consider your Dexterity score and the specific armor available.
4. How does cover affect AC?
Half cover grants +2 to AC and Dexterity saving throws. Three-quarters cover grants +5 to AC and Dexterity saving throws. Full cover means you cannot be targeted directly.
5. Does being prone increase my AC?
No, being prone decreases your AC against melee attacks within 5 feet, as attackers gain advantage on their attack rolls. It increases your AC against ranged attacks from further away as attackers have disadvantage.
6. What’s the best way to increase AC for a Barbarian?
Focus on increasing your Constitution and Dexterity. The Barbarian’s Unarmored Defense feature uses both of these abilities to calculate AC.
7. How do I determine the AC of a monster?
The monster’s stat block will list its AC. This value already incorporates any armor, natural armor, or other defensive abilities it possesses.
8. Can I use multiple shields for even more AC?
No. You can only benefit from one shield at a time.
9. What happens if I have multiple AC calculations?
You choose which calculation to use. You don’t add them together (unless a specific feature says otherwise).
10. Does Mage Armor last indefinitely?
No, Mage Armor lasts for 8 hours.
11. Can I stack the AC bonus from a Ring of Protection with a Cloak of Protection?
No, these bonuses do not stack. Both items provide a bonus to AC and saving throws, and you only benefit from the highest bonus provided by each item type.
12. Does disadvantage on Stealth checks from heavy armor affect my AC?
No. Disadvantage on Stealth checks does not directly affect your AC. It makes you more likely to be heard, potentially leading to combat situations where your AC becomes relevant.
13. How does temporary hit points relate to AC?
Temporary hit points do not directly increase AC. Instead, they absorb damage before your regular hit points are reduced. This effectively makes you harder to defeat but doesn’t change how easy you are to hit.
14. If I multiclass into Monk, do I get to add both Wisdom and Constitution to my AC?
No. You only benefit from one Unarmored Defense feature. You choose which one to use: the Barbarian’s (Constitution) or the Monk’s (Wisdom).
15. Can spells that grant resistance affect AC?
No, resistance reduces the amount of damage you take from certain types of attacks, but it doesn’t increase your Armor Class. It indirectly makes you more durable, but it’s not a direct AC enhancement.