The Interdimensional Conflict was a war where Halo, Star Trek, Fallout, and Star Wars eventually blended together. The resulting conflict destroyed most of the combatants, and the good guys won, like every good war. It also spawned a game, The Interdimensional Conflict, where Private Preston Marlowe from Bad Company finds himself inside 101's armory and with linked worlds, and decided to make 101 a control base and attempt to see what this area was.
When a Stargate gone wrong blended multiple time periods together, new alliances and enemies were formed. The Enclave took one look at the Vohrsoth, the Empire, the CIS, and the Covenant Remnant and decided it was time to purge the galaxy of all life-except themselves. The Forces of Good did not take kindly to this, and the Interdimensional Conflict was born.