Minecraft wiki entry for Creating_a_challenge_map, associated text: Create a maze with netherrack sides at ground level. Set the netherrack on fire. Players will find it hard to complete this maze without a scald. To stop them from jumping over the flames put some floating obsidian, bedrock, or end portal frame blocks, two blocks above the maze path. To make it more challenging for the player, make it a maze that climbs upwards and then add a lever with a sign saying "Trophy," which when pulled will create a lava flow that chases the player, who has to either burn in lava or burn in fire.