From Halopedia, the Halo wiki
LANCER was developed from data recovered from Forerunner war constructs; those data were carefully integrated in a few MJOLNIR [GEN2] components for testing in ANVIL Station. The suit itself was created in the skunkworks departments of ANVIL Station.
The LANCER armor set was originally created as a useable armor permutation for Halo Online, a cancelled Halo 3-derived multiplayer game developed by Saber Interactive and Innova Systems which was intended to be released exclusively in Russia for the PC. After the game's cancellation in 2016, the armor was one of six sets added to Halo 3 in The Master Chief Collection as part of the game's sixth season in 2021.
During the development of Halo Online, the LANCER set was concepted and developed under the name of "SCEPTRE". During the Halo Online Betas, the suit had a notable different backstory to the final revision seen in Halo: The Master Chief Collection.
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