Object Hit Points and size changes

Question

I have a large composite long bow. As stated in the damaging objects rules, it has a hardness of 5 and hit points of 10 (medium would have 5).

Now, when I am holding the bow and under the effects of reduce person, its hit points are halfed, so they become 5, and enlarge person would double them to 20. I understand this part. What I do not understand is how I should be tracking damage as the bow changes size?

As my natural size is large, the bow is made to my size for all the cases below, so it starts with 10 hp. In each of the cases a fighter is running upto me and succeeds on a sunder attempt, dealing 6 damage, and with hardness 5 the bow would take 1 point of damage.

Case 1A: Damage to the bow, what would the hit points be when I increase my size by enlarge person? The new max would be 20 hp, so would the remaining hit points be 19?

Case 1B: Damage to the bow, what would the hit points be when I decrease my size by reduce person? The new max would be 5 hp, so would the remaining hit points be 4?

Case 2: I am under the effect of reduce person so the hp is 5. Damage to the bow. The hp becomes 4. What would the hp be when reduce person is ended?

Case 3: I am under the effect of enlarge person, hp 20. Damage to the bow. The hp becomes 19. What would the hp be when enlarge person is ended?

Answer 1

I don't believe the RAW allow for proportional damage. Hit points change when an object increases or decreases in size.

Each object has hardness—a number that represents how well it resists damage. When an object is damaged, subtract its hardness from the damage. Only damage in excess of its hardness is deducted from the object's hit points.

It makes sense to me that a smaller object is broken more easily. This way an inopportune change in size could break your weapon.

Hit Points: An object's hit point total depends on what it is made of and how big it is ... Objects that take damage equal to or greater than half their total hit points gain the broken condition.

Case 5: Say your large composite long bow takes 8 points of damage. Only 3 points exceed its hardness and now it is -3 for total of 7 hp. When you are hit with reduce person it loses 5 hp and now => 2 hp (less than 1/2 your hp for medium bow.) It's condition is now broken.

However, it doesn't make sense to then be able to be repaired when the spell wears off and it regains the 5 hp. AND the rules don't support that either.

Damaged (but not destroyed) objects can be repaired with the Craft skill and a number of spells. (eg. make whole or mending)

Case 1A: Huge Bow 19hp

Case 1B: Medium Bow 4hp

Case 2: Reduce person ended bow gains 5hp => 9hp

Case 3: Enlarge person - 19hp, wears off lose 10hp => 9hp.

Answer 2

The most 'sensible' way would be to keep proportional damage. After all, the damage (crack or whatever) is changing size along with the weapon.

So you would have the following:

Case 1A: The new max HP is 20HP, the damage increases from 1 to 2. You have 18 HP remaining.

Case 1B: The new max HP is 5, the damage is halved from 1 to 1 (since damage doesn't disappear). You have 4 HP remaining.

Case 2: The new max HP is 10 (doubled from 5), the damage is doubled from 1 to 2. You have 8 HP remaining.

Case 3: The new max HP is 10 (halved from 20), the damage is halved from 1 to 1. You have 9 HP remaining.

There is no precedent for this treatment though.

There is, admittedly, more precedent for treating the damage as in-line with how the rules deal with damage to characters, that it stays the same regardless of other situations. This would cause the weird situation where shrinking an object could break it. Wouldn't be the first time that rules haven't made much physical sense though.