Terraria is a 2011 action-adventure video game developed by Re-Logic and published by 505 Games. As a sandbox game, Terraria has no set goals. After creating the player character and choosing the game's difficulty, the player is placed in a two-dimensional, procedurally generated world where they explore, fight enemies, gather resources, and craft equipment. Players beat bosses, a tougher variety of enemies, to gain access to more items, resources, and equipment. By completing select goals, players receive access to non-player characters (NPCs) who sell items and offer services, such as healing and fishing quests. Terraria can be played alone or with others, and features support for modding.