Dex ACP: Yes Untrained: Yes
You can keep your balance while walking on a tightrope, a narrow beam, a slippery ledge, or an uneven floor. You can also dive, flip, and roll to avoid attacks and overcome obstacles, and land softly after a jump.
There are two general categories of tasks which cover many of the ways that Acrobatics is used: balancing and tumbling. You can also use Acrobatics to avoid attacks of opportunity caused by your movement, and to feint in combat.
You can move on a precarious or narrow surface, or on uneven ground, without falling. A successful check allows you to move at half speed across such surfaces—only one check is needed per round. A failure by 4 or less means that your movement ends, and you can’t move for the rest of the round. A failure by 5 or more means you fall.
The difficulty varies with the condition of the surface (see Table: Perilous Surfaces).
While you are using Acrobatics in this way, you take a −2 penalty to your AC.
If you take damage, if you dodge or block (see Combat Reactions), or if you are subject to a push, grab, trip, or overrun attack (even if you successfully resist the maneuver), you must immediately make another Acrobatics check at the DC of the surface to avoid falling (if you’re balancing on a narrow beam, ledge, or similar) or being knocked prone (if you are on a wide surface). The same applies if you encounter any other hazard that would distract or endanger you.
You must still make this check even if you aren’t moving (i.e. if you’re simply standing still on a perilous surface), or if you haven’t moved more than one-quarter your speed in the past round, but you gain a +5 bonus on your check (as per Careful movement, below).
Poor visibility impairs your ability to balance well. You take a penalty to Acrobatics checks made to move across a perilous surface, equal to your attack roll penalty (for the appropriate level of concealment imposed on your surroundings by prevailing visibility conditions). (See Visibility and Concealment for more information.)
You can try to move across a perilous surface more quickly than normal. If you accept a −5 penalty, you can move your full speed (instead of half speed) as a move action. If you accept a −10 penalty, you can run or charge across a perilous surface.
You can carefully make your way across a perilous surface, moving even slower—at one-quarter speed instead of at half speed. If you do so, you gain a +5 bonus on Acrobatics checks to maintain your balance.
If conditions permit, you may rock, sway, or otherwise disturb the surface that you are balancing on in order to make it more difficult for others. For every −5 penalty you accept to your own check, you force your opponent to make a check at the same penalty. If you fail your check, you fall prone or fall off, as normal.
Disturbing a surface you’re balancing on is a move action, though you may do it as part of your movement. (If you disturb a surface while standing still, you must still make an Acrobatics check to remain standing.)
You can attempt an Acrobatics check at a −10 penalty and use the result as your AC against trip attacks. You must choose to do this before the combat maneuver check to trip you is rolled.
You can attempt an Acrobatics check at a −10 penalty in place of a Reflex save to avoid falling (i.e. into a pit trap). You must choose to do this before you roll the saving throw.
You can land softly when you fall or tumble past opponents. The DCs for various tasks involving tumbling are given on Table: Uses of Tumbling. You can’t tumble if your speed has been reduced by armor or encumbrance. (However, if an ability allows you to move at full speed under such conditions, you can tumble as normal.)
With a successful DC 15 Acrobatics check, you treat an intentional fall (i.e. a jump from a height, or deliberately letting go of a handhold and letting yourself fall) as 10 feet shorter, plus another 10 feet shorter for every 15 by which you exceed the DC; and treat an unintentional fall (i.e. slipping off a ledge, or being pushed off a building) as 10 feet shorter for every 15 by which you exceed the DC. (In other words, for intentional falls, for every 15 points of your Acrobatics check result, you can ignore 10 feet of falling distance when calculating damage. For unintentional falls, the distance which you can ignore is 10 feet less.)
With a successful DC 15 Acrobatics check, you can land on your feet after a fall (rather than being prone, as normal). The DC increases by 10 for every die (d6) of damage which you take from the fall (25 if you take 1d6 damage, 35 if you take 2d6 damage, etc.).
With a DC 30 Acrobatics check, you can stand up from prone as a free action. If you fail this check, you lose your move action and remain prone.
If you move at half speed, you can attempt to move through an opponent’s space. You make an Acrobatics check at a −10 penalty, opposed by a combat maneuver check from your opponent. The penalty is reduced to −5 if your opponent is one size category larger or smaller than you are, and there is no penalty if your opponent is two or more size categories larger or smaller than you are. You automatically succeed on your Acrobatics check when attempting to move through the space of a creature three or more size categories larger or smaller than you are. (This rule applies to creatures of generally humanoid shape; differently shaped creatures may be harder or easier to tumble past.) If your Acrobatics check matches or exceeds your opponent’s combat maneuver check result, you move through their space. If your Acrobatics check is lower than your opponent’s check result, you lose the move action. (In either case, remember that entering an opponent’s space may provoke an attack of opportunity from him; disengaging from an opponent also provokes an attack of opportunity.)
If you take a −5 penalty on your Acrobatics check, you can attempt to move through an opponent’s space while moving at full speed. If you take a −10 penalty, you can attempt to move through an opponent’s space while running or charging.
You can make an Acrobatics check while moving to improve your AC against any attacks of opportunity your movement may provoke (including attacks of opportunity provoked by standing up from prone or from a crouch). If your movement requires an Acrobatics check already (such as if you are moving across a perilous surface—see Balancing, above—or if you are attempting to move through an opponent’s space, or standing up from prone), use the result of that check; otherwise, make an Acrobatics check. In either case, you may use your check result in place of your Armor Class (use whichever is higher).
Apply any dodge bonuses to Armor Class that you may have to your Acrobatics check result (for the purpose of using your check result in place of your Armor Class only; these bonuses are not counted when determining whether you maintain your balance, successfully stand from prone, etc.). (You cannot, however, use a combat reaction to dodge an attack while attempting evasive movement.)
If you attempt evasive movement while moving at half speed or less, you take no penalty on your Acrobatics check. You take a −5 penalty on your Acrobatics check if you are attempting evasive movement while moving at full speed, and a −10 penalty if you are attempting evasive movement while running or charging. (If you are already taking a penalty to your Acrobatics check for moving faster than half speed, such as if you are attempting to charge across a perilous surface, you take no additional penalty due to speed for attempting evasive movement; in other words, moving faster than half speed can only impose a penalty to your Acrobatics check once.)
You can use Acrobatics to feint in combat (see Combat for more information).
Varies. Normally, an Acrobatics check doesn’t require an action; it is made as part of another action, or as a reaction to a situation. Disturbing a surface you are standing on (see Perilous balance, above) is a move action.
You cannot retry most Acrobatics checks, as they are made as reactions or as part of other actions; so you cannot take 20 on an Acrobatics check. You can usually retry the action that required the Acrobatics check, however.
You can’t take 10 on an Acrobatics check made while in combat or while distracted or threatened by a hazard; you could, however, take 10 on a check made to carefully walk across a narrow beam, or perform a similar stunt, if you are not in combat nor threatened at the time.
You can aid an adjacent ally on their Acrobatics check to maintain their balance, granting them a +2 bonus to their check, if you succeed on your own Acrobatics check to maintain your balance. Doing so takes a move action. You can also aid adjacent allies as part of your own movement, but you take a −5 penalty on your own check, and you may not move faster than your ally’s speed. (This applies when two or more characters are moving across a surface together, such as when a party of adventurers is proceeding through a dungeon in marching order.)
You can also can use the Aid Defense combat reaction to improve an ally’s AC, as normal, if she is using Acrobatics to avoid attacks of opportunity caused by movement (see Evasive movement, above).
If you are wearing light armor or no armor, and carrying no more than a light load, then for every 5 ranks in Acrobatics that you have, your dodge value (the dodge bonus to AC that you gain when using your combat reaction to dodge) increases by 1. If you are wearing medium armor, or carrying a medium load, your dodge value increases by 1 for every 10 ranks in Acrobatics that you have, instead of every 5.
Humans with the Heart of the Mountains racial trait get a +2 racial bonus on Acrobatics checks made to keep their balance while moving on narrow surfaces or uneven ground.
Humans with the Heart of the Snows racial trait get a +2 racial bonus on Acrobatics checks made to keep their balance or resist falling while on slippery ground.
Halflings with the Nimble racial trait get a +2 racial bonus on all Acrobatics checks.
The master of a monkey familiar gains a +3 bonus on Acrobatics checks.
A character who is not trained in the Acrobatics skill may not attempt evasive movement.