Spartan Cores were introduced in Halo Infinite, released in 2021 as the upgrade currency for Master Chief's equipment in the campaign. Scattered in cases across Zeta Halo, each core improves abilities such as the Grappleshot, Drop Wall, Threat Sensor and Shield Core when spent at upgrade stations. The pickup sound became familiar to players after hours of exploration, and clips of the cue later spread to soundboards and gaming edits where it is now used as a generic sci fi reward and unlock notification outside the game.