Deus Ex: Invisible War is a 2003 action role-playing video game developed by Ion Storm and published by Eidos Interactive for Microsoft Windows and Xbox. It is the second game in the Deus Ex series. The gameplay—combining first-person shooter, stealth, and role-playing elements—features exploration and combat in environments connected to multiple city-based hubs, in addition to quests that can be completed in a variety of ways and flexible character customization. Conversations between characters feature a variety of responses, with options in conversations at crucial story points affecting how some events play out.