Adding things to armor.

[evyldead]

Is there a way that you can add HP to the wearer of the armor?
Say I wanted to create this: +2 mythral breastplate - +100 HP to wearer.
How would the +100 Hp to wearer be added and cost wise.
And the armor also having No Max Dex Penalty.

Also with another armor type lets go with gauntlets. How would you add a +3 luck bonus to attack and damage on them?

And with boots lets say I want to add movement. Lets say I want to add +30 movement not impeded by ruff turain.

A Ring adding a +4 Shield bonus to AC. And adding let's say invisibility AT WILL ability to the ring also.

[graeylin]

you would follow the rules for crafting magic items... for the armor, however, rather than adding 100 hp to it (which I assume you mean would transfer to you, and not just be for the nonliving armor), you could add magic to give you a heal spell once a day, perhaps. It would depend, does your PC have 100 hp? Or are you looking to be a third level fighter, with 125 hitpoints in this armor?

as for the ring...

start with the ring of force shield:

Force Shield: An iron band, this simple ring generates a shield-sized (and shield-shaped) wall of force that stays with the ring and can be wielded by the wearer as if it were a heavy shield (+2 AC). This special creation has no armor check penalty or arcane spell failure chance since it is weightless and encumbrance-free. It can be activated and deactivated at will as a free action.

Moderate evocation; CL 9th; Forge Ring, wall of force; Price 8,500 gp.

add 20,000 for the ring of invisibility, and add another 24000 gold for the additional +2 to ac, for something roughly around 56,500 gold or so.

[Mehangel]

Would making the armor grant a +2 enhancement bonus to CON work for you? That would effectively increase your hitpoints...

[KillianHawkeye]

A flat addition of hit points from an item is something that really just doesn't exist in 3.x D&D, and I'm pretty sure that's intentional. The most common way to gain hit points is by increasing your Con score, which has a varying effect based on your level and will never be as high as +100 unless you are well into the epic levels.