While most checks follow these basic rules, it’s useful to know about a few specific types of checks, how they’re used, and how they differ from one another.
When you use a Strike action or any other attack action, you attempt a check called an attack roll. Attack rolls take a variety of forms and are often highly variable based on the weapon you are using for the attack, but there are three main types: melee attack rolls, ranged attack rolls, and spell attack rolls. Spell attack rolls work a little bit differently, so they are explained separately on the next page.
Melee attack rolls use Strength as their ability modifier by default. If you’re using a weapon or attack with the finesse trait, then you can use your Dexterity modifier instead.
Ranged attack rolls use Dexterity as their ability modifier.
Ranged attack roll result = d20 roll + Dexterity modifier + proficiency bonus + other bonuses + penalties
When attacking with a weapon, whether melee or ranged, you add your proficiency bonus for the weapon you’re using. Your class determines your proficiency rank for various weapons. Sometimes, you’ll have different proficiency ranks for different weapons. For instance, at 5th level, a fighter gains the weapon mastery class feature, which grants master proficiency with the simple and martial weapons of one weapon group, expert proficiency with advanced weapons of that group and other simple and martial weapons, and trained proficiency in all other advanced weapons.
The bonuses you might apply to attack rolls can come from a variety of sources. Circumstance bonuses can come from the aid of an ally or a beneficial situation. Status bonuses are typically granted by spells and other magical aids. The item bonus to attack rolls comes from magic weapons—notably, a weapon’s potency rune.
Penalties to attack rolls come from situations and effects as well. Circumstance penalties come from risky tactics or detrimental circumstances, status penalties come from spells and magic working against you, and item penalties occur when you use a shoddy item (page 273). When making attack rolls, two main types of untyped penalties are likely to apply. The first is the multiple attack penalty, and the second is the range penalty. The first applies anytime you make more than one attack action during the course of your turn, and the other applies only with ranged or thrown weapons. Both are described below.
Multiple Attack Penalty
The more attacks you make beyond your first in a single turn, the less accurate you become, represented by the multiple attack penalty. The second time you use an attack action during your turn, you take a –5 penalty to your attack roll. The third time you attack, and on any subsequent attacks, you take a –10 penalty to your attack roll. Every check that has the attack trait counts toward your multiple attack penalty, including Strikes, spell attack rolls, certain skill actions like Shove, and many others.
Some weapons and abilities reduce multiple attack penalties, such as agile weapons, which reduce these penalties to –4 on the second attack or –8 on further attacks.
Always calculate your multiple attack penalty for the weapon you’re using on that attack. For example, let’s say you’re wielding a longsword in one hand and a shortsword (which has the agile trait) in your other hand, and you are going to make three Strikes with these weapons during the course of your turn. The first Strike you make during your turn has no penalty, no matter what weapon you are using. The second Strike will take either a –5 penalty if you use the longsword or a –4 penalty if you use the shortsword. Just like the second attack, the penalty for your third attack is based on which weapon you’re using for that particular Strike. It would be a –10 penalty with the longsword and a –8 penalty with the shortsword, no matter what weapon you used for your previous Strikes.
The multiple attack penalty applies only during your turn, so you don’t have to keep track of it if you can perform an Attack of Opportunity or a similar reaction that lets you make a Strike on someone else’s turn.
Ranged and thrown weapons each have a listed range increment, and attacks with them grow less accurate against targets farther away (range and range increments are covered in depth on page 279). As long as your target is at or within the listed range increment, also called the first range increment, you take no penalty to the attack roll. If you’re attacking beyond that range increment, you take a –2 penalty for each additional increment beyond the first. You can attempt to attack with a ranged weapon or thrown weapon up to six range increments away, but the farther away you are, the harder it is to hit your target.
For example, the range increment of a crossbow is 120 feet. If you are shooting at a target no farther away than that distance, you take no penalty due to range. If they’re beyond 120 feet but no more than 240 feet away, you take a –2 penalty due to range. If they’re beyond 240 feet but no more than 360 feet away, you take a –4 penalty due to range, and so on, until you reach the last range increment: beyond 600 feet but no more than 720 feet away, where you take a –10 penalty due to range.
Attack rolls are compared to a special difficulty class called an Armor Class (AC), which measures how hard it is for your foes to hit you with Strikes and other attack actions. Just like for any other check and DC, the result of an attack roll must meet or exceed your AC to be successful, which allows your foe to deal damage to you.
Armor Class is calculated using the following formula.
Armor Class = 10 + Dexterity modifier (up to your armor’s Dex Cap) + proficiency bonus + armor’s item bonus to AC + other bonuses + penalties
Use the proficiency bonus for the category (light, medium, or heavy) or the specific type of armor you’re wearing. If you’re not wearing armor, use your proficiency in unarmored defense.
Armor Class can benefit from bonuses with a variety of sources, much like attack rolls. Armor itself grants an item bonus, so other item bonuses usually won’t apply to your AC, but magic armor can increase the item bonus granted by your armor.
Penalties to AC come from situations and effects in much the same way bonuses do. Circumstance penalties come from unfavorable situations, and status penalties come from effects that impede your abilities or from broken armor. You take an item penalty when you wear shoddy armor (page 273).
Spell Attack Rolls
If you cast spells, you might be able to make a spell attack roll. These rolls are usually made when a spell makes an attack against a creature’s AC.
The ability modifier for a spell attack roll depends on how you gained access to your spells. If your class grants you spellcasting, use your key ability modifier. Innate spells use your Charisma modifier unless the ability that granted them states otherwise. Focus spells and other sources of spells specify which ability modifier you use for spell attack rolls in the ability that granted them. If you have spells from multiple sources or traditions, you might use different ability modifiers for spell attack rolls for these different sources of spells. For example, a dwarf cleric with the Stonewalker ancestry feat would use her Charisma modifier when casting meld into stone from that feat, since it’s a divine innate spell, but she would use her Wisdom modifier when casting heal and other spells using her cleric divine spellcasting.
Determine the spell attack roll with the following formula.
Spell attack roll result = d20 roll + ability modifier used for spellcasting + proficiency bonus + other bonuses + penalties
If you have the ability to cast spells, you’ll have a proficiency rank for your spell attack rolls, so you’ll always add a proficiency bonus. Like your ability modifier, this proficiency rank may vary from one spell to another if you have spells from multiple sources. Spell attack rolls can benefit from circumstance bonuses and status bonuses, though item bonuses to spell attack rolls are rare. Penalties affect spell attack rolls just like any other attack roll—including your multiple attack penalty.
Many times, instead of requiring you to make a spell attack roll, the spells you cast will require those within the area or targeted by the spell to attempt a saving throw against your Spell DC to determine how the spell affects them.
Your spell DC is calculated using the following formula.
Spell DC = 10 + ability modifier used for spellcasting + proficiency bonus + other bonuses + penalties
Perception measures your ability to be aware of your environment. Every creature has Perception, which works with and is limited by a creature’s senses (described on page 464). Whenever you need to attempt a check based on your awareness, you’ll attempt a Perception check. Your Perception uses your Wisdom modifier, so you’ll use the following formula when attempting a Perception check.
Nearly all creatures are at least trained in Perception, so you will almost always add a proficiency bonus to your Perception modifier. You might add a circumstance bonus for advantageous situations or environments, and typically get status bonuses from spells or other magical effects. Items can also grant you a bonus to Perception, typically in a certain situation. For instance, a fine spyglass grants a +1 item bonus to Perception when attempting to see something a long distance away. Circumstance penalties to Perception occur when an environment or situation (such as fog) hampers your senses, while status penalties typically come from conditions, spells, and magic effects that foil the senses. You’ll rarely encounter item penalties or untyped penalties for Perception.
Many abilities are compared to your Perception DC to determine whether they succeed. Your Perception DC is 10 + your total Perception modifier.
Perception for Initiative
Often, you’ll roll a Perception check to determine your order in initiative. When you do this, instead of comparing the result against a DC, everyone in the encounter will compare their results. The creature with the highest result acts first, the creature with the second-highest result goes second, and so on. Sometimes you may be called on to roll a skill check for initiative instead, but you’ll compare results just as if you had rolled Perception. The full rules for initiative are found in the rules for encounter mode on page 468.
There are three types of saving throws: Fortitude saves, Reflex saves, and Will saves. In all cases, saving throws measure your ability to shrug off harmful effects in the form of afflictions, damage, or conditions. You’ll always add a proficiency bonus to each save. Your class might give a different proficiency to each save, but you’ll be trained at minimum. Some circumstances and spells might give you circumstance or status bonuses to saves, and you might find resilient armor or other magic items that give an item bonus.
Fortitude saving throws allow you to reduce the effects of abilities and afflictions that can debilitate the body. They use your Constitution modifier and are calculated as shown in the formula below.
Fortitude save result = d20 roll + Constitution modifier + proficiency bonus + other bonuses + penalties
Reflex saving throws measure how well you can respond quickly to a situation and how gracefully you can avoid effects that have been thrown at you. They use your Dexterity modifier and are calculated as shown in the formula below.
Will saving throws measure how well you can resist attacks to your mind and spirit. They use your Wisdom modifier and are calculated as shown in the formula below.
Sometimes you’ll need to know your DC for a given saving throw. The DC for a saving throw is 10 + the total modifier for that saving throw.
Most of the time, when you attempt a saving throw, you don’t have to use your actions or your reaction. You don’t even need to be able to act to attempt saving throws. However, in some special cases you might have to take an action to attempt a save. For instance, you can try to recover from the sickened condition by spending an action to attempt a Fortitude save.
Basic Saving Throws
Sometimes you will be called on to attempt a basic saving throw. This type of saving throw works just like any other saving throw—the “basic” part refers to the effects. For a basic save, you’ll attempt the check and determine whether you critically succeed, succeed, fail, or critically fail like you would any other saving throw. Then one of the following outcomes applies based on your degree of success—no matter what caused the saving throw.
Critical Success You take no damage from the spell, hazard, or effect that caused you to attempt the save.
Success You take half the listed damage from the effect.
Failure You take the full damage listed from the effect.
Critical Failure You take double the listed damage from the effect.
Pathfinder has a variety of skills, from Athletics to Medicine to Occultism. Each grants you a set of related actions that rely on you rolling a skill check. Each skill has a key ability score, based on the scope of the skill in question. For instance, Athletics deals with feats of physical prowess, like swimming and jumping, so its key ability score is Strength. Medicine deals with the ability to diagnose and treat wounds and ailments, so its key ability score is Wisdom. The key ability score for each skill is listed in Chapter 4: Skills. No matter which skill you’re using, you calculate a check for it using the following formula.
Skill check result = d20 roll + modifier of the skill’s key ability score + proficiency bonus + other bonuses + penalties
You’re unlikely to be trained in every skill. When using a skill in which you’re untrained, your proficiency bonus is +0; otherwise, it equals your level plus 2 for trained, or higher once you become expert or better. The proficiency rank is specific to the skill you’re using. Aid from another character or some other beneficial situation may grant you a circumstance bonus. A status bonus might come from a helpful spell or magical effect. Sometimes tools related to the skill grant you an item bonus to your skill checks. Conversely, unfavorable situations might give you a circumstance penalty to your skill check, while harmful spells, magic, or conditions might also impose a status penalty. Using shoddy or makeshift tools might cause you to take an item penalty. Sometimes a skill action can be an attack, and in these cases, the skill check might take a multiple attack penalty, as described on page 446.
When an ability calls for you to use the DC for a specific skill, you can calculate it by adding 10 + your total modifier for that skill.
Notating Total Modifiers
When creating your character and adventuring you’ll record the total modifier for various important checks on your character sheet. Since many bonuses and penalties are due to the immediate circumstances, spells, and other temporary magical effects, you typically won’t apply them to your notations.
Item bonuses and penalties are often more persistent, so you will often want to record them ahead of time. For instance, if you are using a weapon with a +1 weapon potency rune, you’ll want to add the +1 item bonus to your notation for your attack rolls with that weapon, since you will include that bonus every time you attack with that weapon. But if you have a fine spyglass, you wouldn’t add its item bonus to your Perception check notation, since you gain that bonus only if you are using sight—and the spyglass!—to see long distances.