The basic rules of Pathfinder.
Pathfinder has a reputation for being dense, and its six hundred page manual does nothing to dispel it. Yet everything rests on a handful of mechanics: a twenty-sided die, a modifier, a difficulty class, and three actions to spend on every turn.
Here are those rules gathered in one place, in the order they actually come up at the table. The d20 and the four degrees of success, the six ability scores, rolls and proficiency, the three actions, hit points and the dying condition.
The rule that governs everything.
Every action with an uncertain outcome is settled the same way: a twenty-sided die, a modifier added to the result, and a difficulty class to reach. The modifier adds the relevant ability score to your proficiency, which is your level plus two when trained, plus four when expert, plus six when master, plus eight when legendary. An untrained character adds nothing at all, not even their level.
What sets Pathfinder apart is what comes next. The result does not read as success or failure but in four degrees: beating the difficulty class by ten or more is a critical success, matching it a success, missing it a failure, missing it by ten or more a critical failure. A natural 20 shifts the result one step up, a natural 1 shifts it one step down.
The six ability scores.
It sets melee damage, carrying capacity and manoeuvres like Shove. The fighter in heavy armour cannot do without it.
It gives armour class, ranged attacks and Reflex saves. Many classes make it their key ability.
It adds hit points at every level and feeds the Fortitude save. No class can afford to leave it at the bottom.
It grants extra skills and languages on top of raw knowledge. It is the key ability for the wizard and the alchemist.
Perception and Will both depend on it, two rolls asked for every session. Often the most useful ability outside of combat.
Diplomacy, Intimidation and Deception all run through it. It is also the key ability for the sorcerer, the bard and the champion.
The rolls and proficiency.
A d20, plus the modifier, plus your level if trained, against a difficulty class. All four degrees of success apply to every check.
Fortitude against poison, Reflex against traps, Will against fear and mental magic. Each class advances differently in all three.
A d20 plus proficiency and ability, compared to armour class. Beating it by ten doubles the damage, which is the real stake of every turn.
Untrained, trained, expert, master, legendary: from plus zero to plus eight. Rising proficiency often matters more than a magic item.
It is added to everything you are trained in, which widens gaps fast. A level 10 character succeeds without rolling where a novice always fails.
Circumstance, status and item: two bonuses of the same type never stack. You keep the highest and only add across different types.
The three actions.
On their turn, a character has three actions to spend as they see fit: three attacks, one move and two spells, a manoeuvre and two steps. Nothing is reserved for moving or attacking. Some activities cost two or three actions on their own, a spell often takes two, and turn order is set by a Perception check.
The safeguard is called the multiple attack penalty: the second attack of the turn takes minus five, the third minus ten, and the gap narrows with an agile weapon. Swinging three times is therefore rarely the best use of a turn. Outside their turn, everyone keeps one reaction, only one per round, triggered by a specific situation.
Damage, healing and death.
Every character has hit points, set by their class and Constitution, growing at every level. Armour, resistances and temporary hit points cut down what gets through. As long as that pool is not empty, a wounded character acts exactly like an untouched one.
At zero hit points they fall unconscious and gain the dying condition at value one, or two if a critical hit put them there. On each of their turns a recovery check moves that value up or down: reaching four means death. An ally who heals them puts them back on their feet with the wounded condition, which makes the next fall worse. After that, magical healing, rest and treatment restore hit points.
The rules people get wrong.
Ten points above the DC turns a success into a critical, ten below turns a failure into a critical failure. The rule new tables forget most often.
A natural 20 does not automatically succeed: it improves the result by one degree. On a very hard roll it merely turns a critical failure into a failure.
Three attacks in a turn means the third at minus ten: it almost never lands. Moving, feinting or aiding an ally is usually better.
Two circumstance bonuses do not add up, you keep the better of the two. The same holds for penalties of the same type.
Since the remaster, an untrained character does not add their level. That is exactly what makes being trained in a skill so valuable.
One reaction per round: a parry, a riposte, a shield block, a counterspell. Leaving it unused means playing two thirds of your character.
Applying the rules online.
Counting three actions per character, a multiple attack penalty, bonuses that refuse to stack and a dying value climbing every turn ends up taking more of the game master's attention than the scene itself.
Tomeus gathers the sheets, the dice roller, the backdrop and the music in a single window. You create the game, send the link, and your players arrive with their character in front of them, nothing to install and nothing written on a scrap of paper that goes missing.
Frequently asked questions.
Where can you find the Pathfinder rules for free?
The publisher puts the complete rules online for free and legally, classes, spells, feats and creatures included. It is not an extract or a trimmed version, it is the whole game. The printed books and the beginner box are still worth it for comfortable reading and ready-made adventures.
Which dice do you need to play?
A standard set of seven dice is enough, with the d20 leading for every check. The others mostly cover damage and a few specific effects. Plan for one set per player, or a shared roller if you play online, to avoid passing dice around the table.
What changed between the 2019 and 2023 rules?
The foundation does not move: the d20, the four degrees of success, the three actions, proficiency and saves. The 2023 overhaul renames part of the vocabulary, drops alignment and reworks some classes and spells. Both versions sit at the same table, as long as the group names one of them as the reference for disputed points.