Half-Life: Hostile Takeover

Half-Life: Hostile Takeover is a canceled expansion pack for Half-Life that would have followed Half-Life: Opposing Force as the second official expansion for the game. It would have taken place in Allied Processing, a support facility for Black Mesa which similarly comes under attack by the military after the resonance cascade due to the fact that it contains an interdimensional portal which was used to conduct mining operations in Xen. The player would have assumed the role of a "junior G-Man" who works with the mercenaries from Team Fortress Classic, who are in Allied Processing as its private military guard, to escape the facility.

New enemies would have included the Big Houndeye, a larger version of the Houndeye that was able to emit powerful blasts which could push the player over great distances, and Zombie Monkeys, the result of monkeys in Allied Processing's test labs being zombified by headcrabs. Among the new weapons available to the player were a "Vortigaunt Gun", which could be used to absorb and fire a beam identical to the Vortigaunts' own attacks, a remote-controlled car bomb that the player could drive and detonate under unsuspecting targets, and a laser pointer that could be used to call in a laser strike from a satellite.

The expansion began development in 1999, with news of its existence emerging that November. On March 18, 2000, the expansion's name was revealed with a release date of late August. However, by August 7, the game's publisher, Sierra, announced its cancellation. It was said to have been about 60% done and was roughly playable from start to finish. Neither the developers 2015, Inc. nor the general public were informed of the reason for its cancellation, leaving members of 2015 to speculate that either Valve or Sierra had decided against releasing another expansion pack for Half-Life due to fears of oversaturation in the market.