Orcs Must Die! is an action-tower defense video game developed and published by Robot Entertainment and Mastertronic. It is a tower defense game that eschews the traditional top-down view of similar games, instead using a third-person action-oriented viewpoint. After being demonstrated at Penny Arcade Expo East 2011, the game was released via Xbox Live Arcade on October 5, 2011, and for Windows PCs on October 12, 2011. Gameplay Orcs Must Die! is a variant of a tower defense game; the player as the War Mage must defend one or more Rifts on each level from an onslaught of orcs and other creatures that emerge from one or more entrances and traverse the level. Generally, each orc that reaches a Rift deducts a point from the starting Rift Score while specialized orcs may take off more points; if the Rift Score drops to zero, the level is lost and the player will have to start again. The orc armies arrive in increasingly more difficult waves, with each level having between four and twelve waves. In general, waves will begin a few seconds after the player defeats the prior one, but roughly every three waves on all bar Nightmare difficulty, the player is given a break where they can set up traps and initiate the next wave when they are ready. As the War Mage, the player has the ability to place numerous traps and arm themselves with weapons and equipment to defeat the orcs. The player selects a number of traps and equipment (up to ten) from their current Spellbook; once the player starts placing traps they will be bound to this selection. Traps can be placed on any appropriate surface, but each trap costs in-game currency to place, and traps will have variable costs based on their effectiveness. Traps typically work once and then have a reset period before they will activate again. Such traps include floor, wall, and ceiling traps, and several Guardians that will act on their own accord. The player is given an amount of money to spend on trap placement at the start, and earns more by defeating the orcs and after completing waves; money can also be dropped by certain monsters that must be collected by the player. Traps can be placed at any time, including in combat, and between waves, placed traps can be removed and refunded for their cost. Later, the player gains