Minecraft is a sandbox video game created by Swedish game developer Markus Persson and released by Mojang in 2011. The game allows players to build with a variety of different blocks in a 3D procedurally generated world, requiring creativity from players. Other activities in the game include exploration, resource gathering, crafting, and combat. Multiple gameplay modes are available. These include survival mode in which the player must acquire resources to build the world and maintain health, creative mode where players have unlimited resources to build with and the ability to fly, adventure mode where players can play custom maps created by other players with certain restrictions, and spectator mode where players can freely move throughout a world without being affected by gravity and collisions, or without being allowed to destroy or build anything. There is also hardcore mode, which is similar to survival mode but the player is given only one life, and the game difficulty is locked on hard. If the player dies on hardcore, the player does not respawn, and the world is locked to spectator mode (as of 1.9). The Java Edition of the game allows players to create mods with new gameplay mechanics, items, textures and assets.