Halo Infinite is bringing back the fan-favorite Infection mode in Season 4, with the mode getting a visual touch-up relating to events from Season 3. 343 Industries has also revealed the rules for Halo Infinite’s Infection for those not familiar with the mode.

• Related Reading: Halo Infinite Season 4 Changes, New Content and Trailer Hypes You Up for June 20 Launch

Here are the rules for Infection:

• Infection is a round-based mode where one team (Infected) converts enemy players (Survivors) to their team upon killing them
• Each round, a limited number of players are selected to be Infected – these are Alpha Infected, and the Survivors they kill are converted to Beta Infected
• Survivors start out with limited supplies and will need to acquire additional weapons, equipment, and ammunition from the map
• The goal is for the Infected to eliminate all Survivors. The last Survivor (the Last Spartan Standing) will have special traits applied to them (such as Overshield and unlimited ammo), but a nav-point will reveal their location to all Infected

Infection in the Halo series takes on different forms throughout its various games, with Halo Infinite involving Iratus, the Banished AI, as the source of the “infection.” Iratus takes over a Spartan’s armor, giving them a red, glowing mask above their helmet. Alpha Infected (players who start the game as Infected) will also have even more visual flair to indicate their status compared to Beta Infected (players who turned from Survivors into Infected).

You can read more about Halo Infinite’s rendition of Infection, as well as the history of the game mode, in the official blog post here. Infection launches alongside Season 4 of Halo Infinite on June 20.