When creating Ultima Online, Richard Garriott had grand dreams. Richard and Starr Long planned on implementing a virtual ecology into their massively multiplayer online role-playing game. It was an ambitious system, one that would have cows that graze and predators that eat herbivores. However, once the game went live a small problem had arisen...

1998's Thief: The Dark Project was a pioneer for the stealth genre, utilizing light and shadow as essential gameplay mechanics. The very thing that Thief became so well-known for was also the game's biggest development hurdle. Looking Glass Studios founder Paul Neurath recounts the difficulties creating Thief: The Dark Project, and how its AI systems had to be completely rewritten years into development.

Brad Wardell, founder of Stardock Corporation, details the difficulties in the development of Elemental: War of Magic, a game that shipped in a largely broken state. A memory error caused the development team to pull features from the game in order to fix the issue, but the concern wasn't resolved by the time the game released. As a result, the original vision for Elemental: War of Magic was never fully realized.

Croteam founder Davor Hunski discusses the long development history of the first game in the Serious Sam series. Starting development all the way back in 1996, Serious Sam went through many different iterations, with big shifts occurring every time a new ground-breaking game released. With money running out, Croteam went for a Hail Mary. They crafted a vertical slice that packed all the best bits of the game into one demo.

Today Ars Technica is joined by Warren Spector, designer and director of the highly influential Deus Ex. Released in 2000, Spector set out to create the game of his dreams, one that would blend aspects of stealth, role playing, and first person shooters in innovative ways - and the legacy of his success can be seen across all modern shooting games.

On this edition of War Stories Lee Perry, Gameplay Designer and Level Designer of the original Gears of War, joins Ars Technica to recount how the legendary shooter that spawned a franchise almost left its multiplayer mode ambitions on the cutting room floor.