Every creature in the game is described by six abilities. They are the raw material behind almost every roll you make.
| Ability | Covers |
|---|---|
| Strength | Raw physical force: lifting, shoving, climbing, hitting things hard. |
| Dexterity | Agility and precision: balance, stealth, reflexes, aim. |
| Constitution | Stamina and resilience: how much punishment you absorb. |
| Intelligence | Recall and reasoning: what you know and what you can work out. |
| Wisdom | Perceptiveness and judgement: what you notice and what you sense. |
| Charisma | Force of personality: how well you move other people. |
Each ability has a score, usually between 3 and 20 for a starting character, and what you actually add to a roll is its modifier. The modifier is the score minus 10, halved, rounded down — so a 10 or 11 gives +0, a 16 gives +3, and an 8 gives −1.
| Score | Modifier |
|---|---|
| 8–9 | −1 |
| 10–11 | +0 |
| 12–13 | +1 |
| 14–15 | +2 |
| 16–17 | +3 |
| 18–19 | +4 |
| 20 | +5 |
The score is what your character has. The modifier is what the dice see. Once your scores are set you will barely think about them again — the modifier is the number that ends up on your sheet next to every roll.
Every ability does the same three jobs. It backs ability checks when you try something uncertain, it backs saving throws when something happens to you, and it governs a set of skills — eighteen of them across the six — that narrow an ability to a specific kind of effort. Athletics is Strength applied to climbing and swimming; Arcana is Intelligence applied to magical lore.
A skill never replaces its ability. It is the same roll with training added, and Proficiency is what adds it.