Theme: Athlete - Physical Prowess (6th)

[Moonwalker]

Character Operations Manual, page 9 wrote:

Athletes who chose Acrobatics at 1st level can move at full speed while balancing and do not fall prone on a failed attempt to tumble through an opponent’s square.

What does the quote refer to? There is no rule which says one would fall prone on a failed attempt to tumble through an opponent’s square under the Tumble rules in the Core Rulebook, page 136.

[Sauros]

Not many GMs I've encountered actually use those rules:

Tumble, Page 136 of the CRB wrote:

In all of these cases, the DC is modified by the same environmental circumstances that apply to the balance task of Acrobatics (see page 135).

And so we find on the previous page:

Balance, Page 135 of the CRB wrote:

As part of a move action, you can use Acrobatics to move across narrow surfaces and uneven ground without falling. A successful check allows you to move at half your land speed across such a surface. While balancing, you are flat-footed. If you fail the Acrobatics check to begin moving across a narrow surface or uneven ground, your move action ends at the point just before you’d need to begin balancing. If you fail the check while already balancing (having succeeded on a previous turn), you fall prone and the GM may rule that you start falling, depending on the type of surface you are moving across.

If you take damage while balancing, you must immediately attempt an Acrobatics check at the initial DC. On a success, you remain balancing (and can continue to move if it is your turn). If you fail, you fall prone and, depending on the type of surface you are balancing upon, the GM can rule that you start falling. You can’t take 20 on Acrobatics checks to balance.

[Poit]

Sauros wrote:

Tumble, Page 136 of the CRB wrote:

In all of these cases, the DC is modified by the same environmental circumstances that apply to the balance task of Acrobatics (see page 135).

That's referring to the table of environmental circumstances on pg. 135.

[Moonwalker]

Thank you both for your answers!

I was suspecting the same at first but this explicitly refers to the DC only, not to other Balance rules.

Core Rulebook, page 136 wrote:

In all of these cases, the DC is modified by the same environmental circumstances that apply to the balance task of Acrobatics (see page 135).