Minecraft wiki entry for Defeating_a_Nether_fortress, associated text: First and foremost, if you plan to thoroughly loot the nether fortress, close/farm a blaze spawner, or even just be in the Nether, you'll want Potions of Fire Resistance. These wonders will make you immune to fire and lava damage, which includes blaze ranged attacks and magma cubes melee attacks. The potion, sadly, does not defend from a blaze's melee attack. To make these potions, you need magma cream, which is accessible through a number of ways: