Minecraft wiki entry for Combat, associated text: Magma cubes are common in the Nether, especially near fortresses, so being able to fight them is a necessity for anyone who explores the Nether a lot. Additionally, they are a good source of experience and a useful potion ingredient, magma cream. The smaller two kinds of cube are both easily killed with a stone sword or better even in large numbers, as they have low health and a slow attack rate, but big cubes can be deadly. Due to their jumping attack, they are very hard to hit and dodge, and while they have less health than the player at 8 hearts, they have natural armor that negates some of the damage dealt to them, making their practical health much higher than the player's base. Preferably trap them on a ledge above the player and use a hit and run tactic, but if they must fight them in the open, hit them immediately after their jump so the player has time to escape the next one. Once the big cube is defeated, fighting its smaller counterparts should be much easier.