Evasion Class and Sturdiness Class
Introduction
In 5th Edition of Dungeons and Dragons, Armor Class (AC) is a creature's stat that determines how hard it is to hit them. AC is affected by a large variety of things, often including the creature's Dexterity modifier and (natural) armor. However, while Dexterity is a useful stat for determining how easily a creature can dodge an attack, the purpose of an armor in reality isn't to dodge attacks, but to endure or repel them. As 5e doesn't make this distinction, creatures are a lot tankier than they should be (looking at you, paladins).
For this reason, I'm introducing two new stats: Evasion Class (EC) and Sturdiness Class (SC). EC describes how hard it is to hit a creature, while SC describes how good a creature can endure a hit. The system I propose might make the game a bit more complex and the calculations in section Calculation might look complicated, but effectively you only have to remember one more stat and how Evasion Class and Sturdiness Class relate to attack rolls as shown in section Ruling.
Ruling
If a creature makes an attack roll against you and the result is..
- .. lower than or equal to your EC, the attack misses.
- .. greater than your EC, but equal to or lower than your SC, you only take half of the damage from the attack.
Warning
5th Edition is balanced around the current Armor Class system. A lot more attacks will hit with this system, which means a lot more "hit or suck" effects will come through (at least to some extend). This includes spells, but also feats like Sharpshooter and Great Weapon Master.
Customization
This system offers a lot of options for additional rules and customization.
You could, for example, take into consideration how slashing, piercing and bludgeoning damage affect EC or SC depending on the armor.
Maybe Great Weapon Master's second effect only gives a -2 penalty to attack rolls, but instead of adding damage, it reduces the target's SC by 4, making it very effective against targets with a high SC, but a low EC.
Calculation
AC is affected by a large variety of things, like armor, racial traits, class features, items, feats, magic and cover. Here are some examples how EC and SC could be calculated up to the DM's discretion.
Armor
Armor |
EC |
SC |
|---|---|---|
| Unarmored | ||
| Unarmored | 10 + Dex modifier | 10 + Dex modifier |
| Light Armor | ||
| Padded | 10 + Dex modifier | 11 + Dex modifier |
| Leather | 10 + Dex modifier | 11 + Dex modifier |
| Studded leather | 10 + Dex modifier | 12 + Dex modifier |
| Medium Armor | ||
| Hide | 10 + Dex modifier (max 2) | 12 + Dex modifier (max 2) + Con modifier (max 2) |
| Chain shirt | 10 + Dex modifier (max 2) | 13 + Dex modifier (max 2) + Con modifier (max 2) |
| Scale mail | 10 + Dex modifier (max 2) | 14 + Dex modifier (max 2) + Con modifier (max 2) |
| Breastplate | 10 + Dex modifier (max 2) | 14 + Dex modifier (max 2) + Con modifier (max 2) |
| Half plate | 10 + Dex modifier (max 2) | 15 + Dex modifier (max 2) + Con modifier (max 2) |
| Heavy Armor | ||
| Ring mail | 10 + Dex modifier (max 0) | 14 + Con modifier |
| Chain mail | 10 + Dex modifier (max 0) | 16 + Con modifier |
| Splint | 10 + Dex modifier (max 0) | 17 + Con modifier |
| Plate | 10 + Dex modifier (max 0) | 18 + Con modifier |
| Shield | ||
| Shield | +1 | +2 |
Racial Traits
Some racial traits affect AC. This is how one could transform some of them into the Evasion Class and Sturdiness Class system.
| Trait | EC |
SC |
|---|---|---|
| Natural Armor (Tortle) | 10 + Dex modifier (max 0) | 17 + Con modifier |
| Tortle: Shell Defense | +2 | +4 |
| Natural Armor (Lizardfolk) | 10 + Dex modifier | 13 + Dex modifier |
| Natural Armor (Loxodon) | 10 + Con modifier | 12 + Con modifier |
| Warforged: Integrated Protection | +0 | +1 |
Class Features
Several class features affect AC. This is how one could transform some of them into the Evasion Class and Sturdiness Class system.
| Feature | EC | SC |
|---|---|---|
| Unarmored Defense (Barbarian) | 10 + Dex modifier | 10 + Dex modifier + Con modifier + Str modifier (max 2) |
| Unarmoed Defense (Monk) | 10 + Dex modifier + Wis modifier (max 2) | 10 + Dex modifier + Wis modifier |
| Fighting Style: Defense | +0 | +1 |
| Artificer Infusion: Enhanced Defense | +0 (armor), +0 (shield) | +1 (armor), +1 (shield) |
| Forge Domain Cleric: Soul of the Forge | +0 | +1 |
| Bladesinging Wizard: Bladesong | + Int modifier (max 2) | + Int modifier |
Feats
| Feat | EC | SC |
|---|---|---|
| Dragon Hide | 10 + Dex modifier | 13 + Dex modifier |
| Defensive Duelist | + proficiency bonus | + proficiency bonus |
Items
Several items affect AC. This is how one could transform some of them into the Evasion Class and Sturdiness Class system.
| Item | EC | SC |
|---|---|---|
| Armor +X | +0 | +X |
| Shield +X | +1 | +2+X |
| Ring of Protection | +1 | +1 |
| Cloak of Protection | +1 | +1 |
Magic
Spell |
EC |
SC |
|---|---|---|
| Haste | +2 | +2 |
| Mage Armor | 10 + Dex modifier (max 2) | 13 + Dex modifier (max 2) + Con modifier (max 2) |
| Shield of Faith | +2 | +2 |
| Shield | +5 | +5 |
Cover
| Cover | EC | SC |
|---|---|---|
| Half cover | +2 | +2 |
| Three-quarters cover | +5 | +5 |
Changelog
v2.0
- General. Renamed "Dodge Class" to "Evasion Class"
- Ruling. Removed the second rule about dropping the shield, removed the part about taking a third damage when wearing heavy armor in the third rule
- Armor. Added "+ Con modifier (max 2)" to the SC of all medium armor, added "+ Con modifier" to the SC of all heavy armor, added "+ Dex modifier (max 0)" to the EC of all heavy armor, nerfed the EC bonus of shields to +1 from +2
- Racial Traits. Tortle's natural armor now works like heavy armor, nerfed the EC bonus of Shell Defense to +2 from +4, Loxodon's natural armor now works like light armor
- Class Features. Added "+ Str modifier (max 2)" to Barbarian's Unarmored Defense, nerfed Monk's Unarmored Defense from "+ Wis modifier" to "+ Wis modifier (max 2)", nerfed the EC bonus of the Enhanced Defense Infusion for shields to +0 from +1, nerfed the EC bonus of Bladesong to "+ Int modifier (max 2)" from "+ Int modifier"
- Items. Nerfed the EC bonus of Shield + X to +1 from +2+X
- Magic. Mage Armor now works like medium armor