Ubisoft announced the game at their press conference during Electronic Entertainment Expo 2014. [ 56 ] In August 2015, Ubisoft announced that they had delayed the game's release from October 10 to December 1, 2015, in order to give additional time for the team to balance the game for cooperative multiplayer play. [ 57 ] A closed alpha-testing was held by Ubisoft on April 7–13, 2015, in which players could play an early version of the game in order to help the development team test their servers and core gameplay loops, and to provide feedback. [ 58 ] Ubisoft held a closed beta, starting on September 24, 2015, for further testing. The company originally wanted to hold another round of testing with the release of the game's open beta on November 25, 2015, but they delayed its release to November 26 due to matchmaking issues. [ 59 ] Players who purchased Siege for the Xbox One could download Tom Clancy's Rainbow Six: Vegas and its sequel, Tom Clancy's Rainbow Six: Vegas 2 for free. [ 60 ]