Broken Shields (3.5e Variant Rule)

Broken Shields
Shields aren't very interesting in D&D. They increase your AC, and... well, that's about it. They might give you some special enhancements, but rarely what a suit of armor couldn't do. And by many, they're seen as a "weaker" choice, since you are forced to give up two-handed weapons which can matter a lot in the endgame. On the other hand, a +5 Animated Shield is something that easily bumps someone off the RNG compared to others, which can be just as big of a problem. So instead we change that with this variant.

Mechanics
Shields no longer grant an AC bonus. Instead, as a non-action usable any number of times per round when using a shield with which you are proficient, you may automatically increase your AC by 10 + twice the shield's enhancement bonus against a single attack. This must be declared after an attack is declared against you, but before any attack rolls are made, and cannot be used if you would be denied your Dexterity to AC against that attack.

If the attack misses, the shield loses one durability. If a shield's durability drops to 0 or lower, the shield must make a Fortitude save (DC equal to 15 + the amount of damage dealt after factoring in hardness, as per the smashing an object rules) or break, becoming almost useless (see below on what happens when a shield breaks). The shield's effective hardness drops by two for every negative point of durability it possesses (for example, a shield with -2 durability would have 4 less hardness than normal), and if the shield's hardness reaches 0, it automatically breaks. As durability drops (even to 0 and below), the shield doesn't take any actual damage, only the hardness is reduced.

It is possible to repair a shield by spending five minutes to maintain it, resetting its durability to the maximum possible, while the mending spell increases the durability by one (up to its maximum) and the make whole spell completely repairs the shield. If a shield splinters, it is no longer usable except by being readied (see below), but you still take all the normal penalties while equipping it (arcane spell failure, armor check penalty, penalty to using things in the same hand as the shield, and so on), and must use the normal kind of action to divest yourself of the shield as you would were it whole.

A shield's durability is equal to its innate durability (as per the table below) plus its enhancement bonus to AC. Thus, a +2 Darkwood Heavy Fortification Buckler would have a durability of 3, while a +5 Animated Adamantine Tower Shield would have a durability of 10. Once a shield breaks, you are unable to use it unless you spend a move action to ready it. When you use it in this way, you may only block a single attack (or spell) per round.

Spells that deal damage, as well as melee and ranged touch attacks may also be blocked by a shield, but require the expenditure of two points of durability instead of one. If you use a shield in this way to block a spell, instead gain a bonus equal to 5 + the shield's enhancement bonus to your save against the spell (you may use this after rolling your save), and you take no damage or any of the effects on a successful save (though your shield takes full damage as though it had failed the save for the purposes of the DC against breaking if its durability falls to 0 or lower). A tower shield may be used to block any spell that requires a saving throw to resist, and when reduced to 0 durability, if the spell does not normally deal damage, consider the damage to be equal to twice the spell's level added to twice the caster level of the spellcaster.