Blindmage wrote:
However:
Carrying Capacity wrote:
A medium or heavy load counts as medium or heavy armour for the purpose of abilities or skills that are restricted by armour. Carrying a light load does not encumber a character.
That only refers to abilities like Evasion which only work if you're in no heavier than Light armor for a Rogue, or Unarmored for a Monk. It doesn't mean that a Medium load is covered under Medium Armor Proficiency. However, there are two separate blocks of rules in play here:
PRD wrote:
Armor Check Penalty: Any armor heavier than leather, as well as any shield, hurts a character's ability to use Dexterity- and Strength-based skills. An armor check penalty applies to all Dexterity- and Strength-based skill checks. A character's encumbrance may also incur an armor check penalty.
...
Nonproficient with Armor Worn: A character who wears armor and/or uses a shield with which he is not proficient takes the armor's (and/or shield's) armor check penalty on attack rolls as well as on all Dexterity- and Strength-based ability and skill checks. The penalty for nonproficiency with armor stacks with the penalty for shields.
The main block describing ACP states that encumbrance may also incur an armor check penalty. But it isn't until the "Non-proficient with armor Worn" section where it describes that being non-proficient with the armor is what expands the check penalty to include attack rolls as well. Well, there's no proficiency for encumbrance, but encumbrance isn't armor. So, the question becomes, which is the default state and which establishes the exception? Is the default state non-proficiency with the ACP applied to attack rolls, and proficiency prevents it from affecting attack rolls? Or is the default state considered proficiency and if you try to operate outside that proficiency, the exceptional state is that your ACP now applies to attack rolls? In the first case, ACP from encumbrance would apply to attack rolls because the default presumption is that you automatically have a penalty to attack rolls unless you're proficient with whatever is imparting the ACP and you cannot be proficient with medium or heavy loads. In the second case, you're presumed not to have the penalty because you're presumed to be operating within your proficiency; ergo, since Non-proficiency is concerning armor only, it only applies to medium or heavy armor and not medium or heavy loads. It's somewhat ambiguous and, while option A makes more reasonable sense, option B is slightly more implied by strict RAW.
