How many Acrobatics checks are needed to pass through a medium creature's threatened area via its space?

Question

I'm trying to understand how using Acrobatics to avoid attacks of opportunity works.

The green dot is the creature that wants to move past its foe without provoking any attacks of opportunity. The red dot is the foe, and the blue dot is the square that the green creature wants to reach. The light-blue area is the foe's threatened area. Both the creature and the foe are medium size.

Considering that:

• The red foe's threatened area includes its own space

• A creature has to make an Acrobatics check for each threatened square it leaves

• Entering an enemy's space provokes an AoO "should be considered" (IIRC) aside from moving out from a threatened square

Assuming every check is successful, how many Acrobatic checks does the creature need to get from the green to the blue square, through the foe at the red square?

Answer 1

One, at +5 DC

The assumption that a separate check is made for each square is incorrect, as indicated by this FAQ entry provided by HeyICanChan. As both that and the Acrobatics table entry indicate, if your move takes you through an enemy's square, you increase the DC by 5, which is the case here.

In addition, it states the following as a special rule for the case of moving through an opponent's space:

If you attempt to move through an enemy’s space and fail the check, you lose the move action and provoke an attack of opportunity.

Thus, if that check was failed, the green dot would stop in square 1 and lose the rest of its move, in addition to provoking an AoO.