Deus Ex: Human Revolution is the third game in the Deus Ex franchise. It is a stealth-action game, where the player must infiltrate a heavily guarded research facility to collect an unknown form of Augmented Reality technology, called the Human Augmentation. The game starts with the creation of the first Human Augmentation, and the world of Human Augmentation is introduced to the player in the first level. The player must choose to be either the good guy or the bad guy, and his actions will determine the outcome of the story. The main storyline is based on a series of stealth missions, where the player must complete them in order to advance in the game. Each mission is completed by sneaking past various security guards and unlocking a specific door.