Combat is played with various sided dice. You make attack rolls against defense numbers and deal damage against hit points.
Combat Stats
Initiative Bonus
Your initiative bonus is your Dexterity modifier + your level.
Attack Bonuses
For each attack, roll a d20 + an ability bonus + your level (+ magic item attack bonus, if any). Depending on the attack, you might also get other bonuses. Compare your total to the target’s defense, usually Armor Class but sometimes Physical Defense or Mental Defense. If the total is equal to or higher than the defense, you hit. If you attack multiple targets, make multiple attack rolls. Your class defines which ability bonus you use on attack rolls, and the attack defines the effects of a hit or a miss.
Damage
Each attack indicates a specified amount of damage it does; subtract that amount from the target’s hit points. If the attack targets multiple enemies, you make a separate attack roll for each one, but only roll damage once.
Damage totals for your attacks are calculated by adding one ability score modifier to the attack’s damage roll, normally represented by saying “+ Ability.”
Calculate the ability modifier subtracting 10 from the ability score, halving the result, then rounding down.
At 5th level, double the ability score modifier before adding to the damage roll for all attacks. (Negative modifiers get are doubled too).
At 8th level, triple the ability score modifier.
Spells indicate a specific number of dice to roll for damage. Weapon attacks work differently.
Weapons
Weapons are rated by how much damage they deal. In the hands of player characters, each weapon attack deals 1 die of damage per character level + ability modifier, notated as WEAPON + [Ability].
Each class has its own version of the weapon chart, showing how well members of the class use weapons of a given damage category.
Other Damage Types
Different monsters and characters may be resistant or vulnerable to various types of damage, including:
- Acid
- Cold
- Fire
- Force
- Holy
- Lightning
- Negative energy
- Poison
- Psychic
- Thunder (sonic energy)
Defenses
There are three different defenses: Armor Class, Physical Defense, and Mental Defense. Each uses three ability scores as part of its calculation. PCs also add their class level to their defenses.
Armor Class (AC)
AC protects you from weapon attacks. It is equal to the middle value among Con, Dex, and Wis. Disregard the higher and the lower values.
Physical Defense (PD)
PD protects you from other physical attacks. It is equal to the middle value among Str, Con, and Dex. Disregard the higher and the lower values.
Mental Defense (MD)
MD protect you against mental attacks. It is equal to the middle value among Int, Wis, and Cha. Disregard the higher and the lower values.
Hit Points
Hit points are based on class, Con modifier, and level. See the level progression chart for each class.
Speed
If it’s important to know who covers ground faster, the GM determines how to make the “speed check” by using either common sense or stats and skills.
Stacking Rules
Bonuses and effects to a single stat stack with each other, with these exceptions:
- Magic item bonuses don’t stack. Only the best one counts.
- Many condition penalties don’t stack. Only the worst one counts.
- Powers, spells, and abilities don’t stack with themselves or with other game elements with the same name. This works for both PCs and monsters.