armor check penalty (ACP)

[jrizz]

does ACP affect reflex rolls? dodge? uncanny dodge?

[gilshem ironstone]

Only skills based on your dexterity score are affected.

[Filatus]

Including tumble, which is the most important consequence for someone without spring attack.

[Script Wrecked]

Armor check penalty:

An armor check penalty applies to most dexterity-based skills when a character wears armor heavier than leather. This penalty is used instead of the maximum dexterity bonus, and it applies to hide, move silently, parry, pick pocket, set trap, and tumble. The only dexterity-based skill not on this list is open lock, to which neither the maximum dexterity bonus nor the armor check penalty applies.