For a low-magic or non-magic campaign I had come up with some rules for expanding on the normal mastercrafting rules for weapons, armor, and equipment.
You can make a masterwork item: a weapon, suit of armor, shield, or tool that conveys a bonus on its use through its exceptional craftsmanship. To create a masterwork item, you create the masterwork component as if it were a separate item in addition to the standard item. The masterwork component has its own price and Craft DC according to the level of mastercraft achieved (up to level 5 for non-epic items). Once both the standard component and the masterwork component are completed, the masterwork item is finished. The cost you pay for the masterwork component is one-third of the given amount, just as it is for the cost in raw materials.
The Craft DC for completing the Masterwork component of any item depends on its level.
Masterwork 1 Craft DC 20
Masterwork 2 Craft DC 25
Masterwork 3 Craft DC 30
Masterwork 4 Craft DC 35
Masterwork 5 Craft DC 40
Masterwork Components of Weapons [all bonuses are nonmagical]
Masterwork 1 (300 gp) +1 to attack
Masterwork 2 (1,200 gp) as above, plus add 1 to damage
Masterwork 3 (2,700 gp) as above, plus reduce weight by 25%
Masterwork 4 (4,800 gp) as above, plus increase hardness by 1 and break DC by 2
Masterwork 5 (7,500 gp) as above, plus the weapon can be wielded as though its size category were one step lower (light weapons take no TWF penalties to attacks). This benefit only applies as long as the weapon is regularly maintained and kept in good condition, at least once per week. This requires a Craft check (against DC 20). You can Take 10 with this check but not Take 20.
Masterwork Components of Armor (excludes shields)
Masterwork 1 (150 gp) reduce armor check penalty by 1 (minimum zero)
Masterwork 2 (600 gp) as above, plus weight reduced by 25%
Masterwork 3 (1,350 gp) as above, plus max dexterity bonus increases by 1
Masterwork 4 (2,400 gp) as above, plus armor/shield bonus increases by 1
Masterwork 5 (3,750 gp) as above, plus armor can be worn as though its size category were one step lower (light armor counts as unarmored) as long as the armor is kept regularly maintained and in good condition, at least once per week. This requires a Craft/armor check (against DC 20). You can Take 10 with this check but not Take 20.
Masterwork Components of Shields
Masterwork 1 (150 gp) reduce armor check penalty by 1
Masterwork 2 (600 gp) as above, plus weight reduced by 25%
Masterwork 3 (1,350 gp) as above, plus:
* Tower shields: increase max dexterity bonus by 1
* Heavy shields: you can carry other items (other than weapons) in the hand gripping the shield, as though it were a light shield instead
* Light shields: you can hold a weapon in your shield-hand and fight with it as though you were wielding a buckler instead
Bucklers: you take no penalty on attack rolls when wielding a weapon with your shield arm.
Masterwork 4 (2,400 gp) as above, plus armor/shield bonus increases by 1
Masterwork 5 (3,750 gp) as above, plus add 1 to shield-bashing damage. as long as the shield is regularly maintained and kept in good shape at least once per week. This requires a relevant Craft/armor check (against DC 20). You can Take 10 with this check but not Take 20.
Masterwork Components of Other Items
Cost for masterwork items beyond level 1 equals the mastercraft-level squared times the masterwork component of the item, such as:
Mastercraft artisan's tools:
masterwork 1 (50 gp) grants +2 circumstance bonus to relevant Craft checks
masterwork 2 (200 gp) as above, plus reduce weight by 25%
masterwork 3 (450 gp) as above, plus artisan's tools can still be used as "improvised" tools even if broken, imposing only a -1 on Craft checks for using improvised tools
masterwork 4 (800 gp) as above, plus increase hardness by 1 and break DC by 2
masterwork 5 (1,250 gp) as above, but granted circumstance bonus increases to +5 as long as the tool is regularly maintained and kept in good condition, at least once per week. This requires a Craft check with the relevant Craft skill (against DC 20). You can Take 10 with this check but not Take 20.
Mastercraft musical instruments:
[I am taking some license with the normal cost of masterwork instruments and using a cost of 105 gp to allow for some well-rounded numbers.]
masterwork 1 (100 gp) grants +2 circumstance bonus to Perform checks
masterwork 2 (400 gp) as above, plus reduce weight by 25%
masterwork 3 (900 gp) as above, plus ?????
masterwork 4 (1,600 gp) as above, plus increase hardness by 1 and break DC by 2
masterwork 5 (2,500 gp) as above, plus granted circumstance bonus can be increased to +5 if the instrument is kept finely-tuned at least once per week. This requires a Perform check (against DC 20). You can Take 10 with this check but not Take 20.
Thieves' tools:
masterwork 1 (70 gp) grants +2 circumstance bonus on Disable Device checks
masterwork 2 (280 gp) as above, plus reduce weight by 25%
masterwork 3 (630 gp) as above, plus ?????
masterwork 4 (1,120 gp) as above, plus increase hardness by 1 and break DC by 2
masterwork 5 (1,750 gp) as above, plus granted circumstance bonus can be increased to +5 if the tools are well-maintained and keep in good condition at least once per week. This requires a Craft check (against DC 20). You can Take 10 with this check but not Take 20.
I'm not really sure what I could input as a benefit for masterwork level 3 items of the last few types...
You can make a masterwork item: a weapon, suit of armor, shield, or tool that conveys a bonus on its use through its exceptional craftsmanship. To create a masterwork item, you create the masterwork component as if it were a separate item in addition to the standard item. The masterwork component has its own price and Craft DC according to the level of mastercraft achieved (up to level 5 for non-epic items). Once both the standard component and the masterwork component are completed, the masterwork item is finished. The cost you pay for the masterwork component is one-third of the given amount, just as it is for the cost in raw materials.
The Craft DC for completing the Masterwork component of any item depends on its level.
Masterwork 1 Craft DC 20
Masterwork 2 Craft DC 25
Masterwork 3 Craft DC 30
Masterwork 4 Craft DC 35
Masterwork 5 Craft DC 40
Masterwork Components of Weapons [all bonuses are nonmagical]
Masterwork 1 (300 gp) +1 to attack
Masterwork 2 (1,200 gp) as above, plus add 1 to damage
Masterwork 3 (2,700 gp) as above, plus reduce weight by 25%
Masterwork 4 (4,800 gp) as above, plus increase hardness by 1 and break DC by 2
Masterwork 5 (7,500 gp) as above, plus the weapon can be wielded as though its size category were one step lower (light weapons take no TWF penalties to attacks). This benefit only applies as long as the weapon is regularly maintained and kept in good condition, at least once per week. This requires a Craft check (against DC 20). You can Take 10 with this check but not Take 20.
Masterwork Components of Armor (excludes shields)
Masterwork 1 (150 gp) reduce armor check penalty by 1 (minimum zero)
Masterwork 2 (600 gp) as above, plus weight reduced by 25%
Masterwork 3 (1,350 gp) as above, plus max dexterity bonus increases by 1
Masterwork 4 (2,400 gp) as above, plus armor/shield bonus increases by 1
Masterwork 5 (3,750 gp) as above, plus armor can be worn as though its size category were one step lower (light armor counts as unarmored) as long as the armor is kept regularly maintained and in good condition, at least once per week. This requires a Craft/armor check (against DC 20). You can Take 10 with this check but not Take 20.
Masterwork Components of Shields
Masterwork 1 (150 gp) reduce armor check penalty by 1
Masterwork 2 (600 gp) as above, plus weight reduced by 25%
Masterwork 3 (1,350 gp) as above, plus:
* Tower shields: increase max dexterity bonus by 1
* Heavy shields: you can carry other items (other than weapons) in the hand gripping the shield, as though it were a light shield instead
* Light shields: you can hold a weapon in your shield-hand and fight with it as though you were wielding a buckler instead
Bucklers: you take no penalty on attack rolls when wielding a weapon with your shield arm.
Masterwork 4 (2,400 gp) as above, plus armor/shield bonus increases by 1
Masterwork 5 (3,750 gp) as above, plus add 1 to shield-bashing damage. as long as the shield is regularly maintained and kept in good shape at least once per week. This requires a relevant Craft/armor check (against DC 20). You can Take 10 with this check but not Take 20.
Masterwork Components of Other Items
Cost for masterwork items beyond level 1 equals the mastercraft-level squared times the masterwork component of the item, such as:
Mastercraft artisan's tools:
masterwork 1 (50 gp) grants +2 circumstance bonus to relevant Craft checks
masterwork 2 (200 gp) as above, plus reduce weight by 25%
masterwork 3 (450 gp) as above, plus artisan's tools can still be used as "improvised" tools even if broken, imposing only a -1 on Craft checks for using improvised tools
masterwork 4 (800 gp) as above, plus increase hardness by 1 and break DC by 2
masterwork 5 (1,250 gp) as above, but granted circumstance bonus increases to +5 as long as the tool is regularly maintained and kept in good condition, at least once per week. This requires a Craft check with the relevant Craft skill (against DC 20). You can Take 10 with this check but not Take 20.
Mastercraft musical instruments:
[I am taking some license with the normal cost of masterwork instruments and using a cost of 105 gp to allow for some well-rounded numbers.]
masterwork 1 (100 gp) grants +2 circumstance bonus to Perform checks
masterwork 2 (400 gp) as above, plus reduce weight by 25%
masterwork 3 (900 gp) as above, plus ?????
masterwork 4 (1,600 gp) as above, plus increase hardness by 1 and break DC by 2
masterwork 5 (2,500 gp) as above, plus granted circumstance bonus can be increased to +5 if the instrument is kept finely-tuned at least once per week. This requires a Perform check (against DC 20). You can Take 10 with this check but not Take 20.
Thieves' tools:
masterwork 1 (70 gp) grants +2 circumstance bonus on Disable Device checks
masterwork 2 (280 gp) as above, plus reduce weight by 25%
masterwork 3 (630 gp) as above, plus ?????
masterwork 4 (1,120 gp) as above, plus increase hardness by 1 and break DC by 2
masterwork 5 (1,750 gp) as above, plus granted circumstance bonus can be increased to +5 if the tools are well-maintained and keep in good condition at least once per week. This requires a Craft check (against DC 20). You can Take 10 with this check but not Take 20.
I'm not really sure what I could input as a benefit for masterwork level 3 items of the last few types...
