Armor check penalty

Armor Check Penalty (ACP): The Penalty to Skills due to the restrictiveness of certain armor.

The following are subject to ACP:
 * Balance
 * Hide
 * Jump
 * Move Silently
 * Tumble
 * Swim is subject to double the standard ACP

Carrying Capacity also can cause an ACP.
 * Medium encumbrance causes a -3
 * Heavy encumbrance causes a -6

Non-proficiency with a certain armor or shield will apply the ACPs to all attack rolls, Strength based skills and Dexterity based skills. Non-proficiency penalties from armor and shields stack.