Minecraft wiki entry for Exploring_caves, associated text: Armor - As said before, lots of mobs spawn in caverns because of the low light level. Iron or higher tier armor may be needed when exploring caves, so as to give the player better protection against mobs. Exploring without armor is very dangerous, as mobs can kill an unarmored player in just a few hits. Armor can also be enchanted to have Fire Protection (for lava and burning), Projectile Protection (for skeleton's arrows), Feather Falling (for falling damage), etc.