Do resistances from class/race and magic items stack?

Question

I'm just curious about some details regarding damage resistance in D&D 4e.

Do resistance effects granted by class/racial features stack with resistances granted by magical items?

Answer 1

Resistance doesn't stack unless it's from two different damage types, it's source doesn't usually matter. In a situation were you have resistance of the same damage type, only the highest of the two applies.

From the Rules Compendium:

Resistance against the same damage type are not cumulative. Only the highest resistance applies. (pg.225)

For example; if you're a level 6 Tielfling than you have resistance to 8 fire damage as a racial feature. If you were to acquire some Black Iron Armour (PHB1 pg.227), you wouldn't have resist 13 fire, you would still only have resist 8 because the resistance granted by your racial feature is the highest of the two.
You would however gain the resist 5 necrotic because it is of a different type of damage.

Answer 2

Only if the resistances are to different types of damage. If they are to the same type of damage, only the higher applies.

There are pseudo-exceptions, but they stick out like a sore thumb, because they explicitly say things like, "or your existing resistance to Fire is increased by 5," which still isn't really the same thing as stacking. If neither game element you're looking at has text like that, they don't stack.