Armory Marine glitch
This glitch was an exploit in Halo 5: Guardians where an attacking player could cause Marine Replicants in Warzone Assault to commit suicide, allowing players to capture Armories before the first base.
An attacking player could activate this exploit by approaching an Armory before the prior base had been captured. Though the player would be unable to enter the Armory due to its shield walls, enemy Marines would still try to attack them. However, their bullets would bounce off the shield wall and eventually kill the Marines.
After the Marines were dead, players could then climb on top of the Armory to capture it. There would be no capture indicator, but Sarah Palmer voiceover would note the Armory as nearing capture. With the Armory captured, attackers would be given an extra six minutes to capture the first base to open the Core for attack.
The glitch was patched in December 2015 with the Cartographer's Gift update.