Draconic Armor( Dragon Magic, p. 16)
You learn to block damage from successful attacks, lessening the blows with spell energy.
Draconic Heritage (DM) , sorcerer le%"el 1st,
Whenever you cast an arcane spell, you gain damage reduction X/magic for 1 round (where X is equal to the level of the spell you just cast). For example, alter casting fireball, you would gain DR 3/magic for 1 round.