Orcs Must Die!

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 access to Weavers, who for various costs can boost certain effects on the player or traps placed in the manner of a technology tree; these effects only last for that level. Once the player initiates a wave, they can run about the level to participate in combat or place additional traps. The player must watch their health and mana used for their weapons but orcs may drop health and mana potions that will replenish these; alternatively the player can heal while in proximity of the Rift. If the player should lose all their health or fall off the level, they will respawn back at the Rift but this will cost them a number of Rift Points. After defeating the last wave, the player is awarded a number of skulls, up to 5 (or on Apprentice difficulty, limited to two), based on their score (reflecting how many Rift points remain) and the time needed to defeat all the waves. Skulls are used to buy improvements to traps and weapons in the player's spellbook, such as increasing damage, reducing cost, or making them more effective against the orcs. The player, after completing each level the first time, is also rewarded with a new trap type for their Spellbook they can use in subsequent levels. These improvements remain with the player, so that they may return to earlier levels with these improved traps to earn more skulls. ==Plot==