Tiger Engine is Bungie's proprietary technology, with roots tracing back to the Blam! engine the studio used for the classic Halo games. After Bungie split from Microsoft and began work on Destiny, the engine was substantially rebuilt and renamed Tiger Engine — retooled for the demands of a persistent live-service looter shooter with constant content updates, rather than a single-player campaign. The same technology now powers Marathon, Bungie's PvP extraction shooter — the studio deliberately chose not to switch to a third-party engine like Unreal, opting instead to keep expanding Tiger Engine so it could serve multiple projects at once.
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