Checks

When success isn’t certain—whether you’re swinging a sword at a foul beast, attempting to leap across a chasm, or straining to remember the name of the earl’s second cousin at a soiree—you’ll attempt a check. Pathfinder has many types of checks, from skill checks to attack rolls to saving throws, but they all follow these basic steps.

1. Roll a d20 and identify the modifiers, bonuses, and penalties that apply.
2. Calculate the result.
3. Compare the result to the difficulty class (DC).
4. Determine the degree of success and the effect.

Checks and difficulty classes (DC) both come in many forms. When you swing your sword at that foul beast, you’ll make an attack roll against its Armor Class, which is the DC to hit another creature. If you are leaping across that chasm, you’ll attempt an Athletics skill check with a DC based on the distance you are trying to jump. When calling to mind the name of the earl’s second cousin, you attempt a check to Recall Knowledge. You might use either the Society skill or a Lore skill you have that’s relevant to the task, and the DC depends on how common the knowledge of the cousin’s name might be, or how many drinks your character had when they were introduced to the cousin the night before.

Pathfinder has many specific rules, but you’ll also want to keep these general guidelines in mind when playing.

The GM Has the Final Say

If you’re ever uncertain how to apply a rule, the GM decides. Of course, Pathfinder is a game, so when adjudicating the rules, the GM is encouraged to listen to everyone’s point of view and make a decision that is both fair and fun.

Specific Overrides General

A core principle of Pathfinder is that specific rules override general ones. If two rules conflict, the more specific one takes precedence. If there’s still ambiguity, the GM determines which rule to use. For example, the rules state that when attacking a concealed creature, you must attempt a DC 5 flat check to determine if you hit. Flat checks don’t benefit from modifiers, bonuses, or penalties, but an ability that’s specifically designed to overcome concealment might override and alter this. If a rule doesn’t specify otherwise, default to the general rules presented in this chapter. While some special rules may also state the normal rules to provide context, you should always default to the normal rules even if effects don’t specifically say to.

Rounding

You may need to calculate a fraction of a value, like halving damage. Always round down unless otherwise specified. For example, if a spell deals 7 damage and a creature takes half damage from it, that creature takes 3 damage.

Multiplying

When more than one effect would multiply the same number, don’t multiply more than once. Instead, combine all the multipliers into a single multiplier, with each multiple after the first adding 1 less than its value. For instance, if one ability doubled the duration of one of your spells and another one doubled the duration of the same spell, you would triple the duration, not quadruple it.

Duplicate Effects

When you’re affected by the same thing multiple times, only one instance applies, using the higher level of the effects, or the newer effect if the two are the same level. For example, if you were using mage armor and then cast it again, you’d still benefit from only one casting of that spell. Casting a spell again on the same target might get you a better duration or effect if it were cast at a higher level the second time, but otherwise doing so gives you no advantage.

Ambiguous Rules

Sometimes a rule could be interpreted multiple ways. If one version is too good to be true, it probably is. If a rule seems to have wording with problematic repercussions or doesn’t work as intended, work with your group to find a good solution, rather than just playing with the rule as printed.

No matter the details, for any check you must roll the d20 and achieve a result equal to or greater than the DC to succeed. Each of these steps is explained below.

Step 2: Calculate the Result

This step is simple. Add up all the various modifiers, bonuses, and penalties you identified in Step 1—this is your total modifier. Next add that to the number that came up on your d20 roll. This total is your check result.

Step 3: Compare the Result to the DC

This step can be simple, or it can create suspense. Sometimes you’ll know the Difficulty Class (DC) of your check. In these cases, if your result is equal to or greater than the DC, you succeed! If your roll anything less than the DC, you fail.

Other times, you might not know the DC right away. Swimming across a river would require an Athletics check, but it doesn’t have a specified DC—so how will you know if you succeed or fail? You call out your result to the GM and they will let you know if it is a success, failure, or otherwise. While you might learn the exact DC through trial and error, DCs sometimes change, so asking the GM whether a check is successful is the best way to determine whether or not you have met or exceeded the DC.

Calculating DCs

Whenever you attempt a check, you compare your result against a DC. When someone or something else attempts a check against you, rather than both forces rolling against one another, the GM (or player, if the opponent is another PC) compares their result to a fixed DC based on your relevant statistic. Your DC for a given statistic is 10 + the total modifier for that statistic.