A Small Mithral Dagger costs 402 GP, rather than 252 (cheaper than masterwork!)
New Magic Ability (weapons and armor):
Resizable: The weapon or armor can change size like other magic items. Cost: +1 bonus. Shrink Item, Craft Wondrous. Moderate Transmutation (?). NOTE: Pathfinder changed things more than I realized, and this is actually “default” for magic armor and weapons as far as I can tell. However, this is still a magic property that can be added to let weapons change size at the wielders will.
Intelligent items of any kind can change their size at will, but only to their default size, or the size of their current wielder.
Any magic item that can change size remains in its size for 24 hours even if put down before reverting to its natural size.
Darkwood and Mithral prices are based on the default size.
Intelligent Items that can cast spells may cast any spells with a target of “self” on the creature carrying them instead. If they have a spell that has a specific target other than self, they can cast the spell as an Immediate action when they successfully hit an opponent (or are hit by an opponent) if they do not take any other action that turn. In effect, they are assumed to have Readied to cast their spell based on dealing damage, unless they declare any actions. In all cases, an intelligent item is assumed to act at the same initiative as the creature holding them. Intelligent items can cast any spells they know with no components. However, any costly focus materials should be incorporated into their construction, and 5x any expensive material components should be used in their making.
In-Character “+1” Descriptions:
Items that have modifiers ranging from +1 to +5 (for example, Rings of Protection, weapons, armor) will be described as “Least”, “Lesser”, “Moderate”, “Greater”, and “Great” (for example, a “Lesser Mithral Chainshirt” is a +2 Mithral Chainshirt). Items with modifiers of +2, +4, +6 will be “Lesser”, “Moderate”, and “Greater”. This keeps them similarly named to other items. Other numeric classifications will be converted in a similar manner.