Marathon Season 3 could be shaping up to be Bungie’s biggest update yet. A new leak allegedly originating from a recent private playtest has revealed extensive details about the upcoming PvE experience, including four connected runs, several bosses, a major Perimeter expansion, new weapons, Flash Boosts, and progression changes.
Bungie has officially confirmed that Season 3 begins on September 22, 2026, bringing its full PvE mode alongside major new areas and encounters in Perimeter, a new Runner shell, weapons, and equipment. However, the more detailed gameplay information below remains unconfirmed and could change before release.
In brief
- A leak claims Marathon’s Season 3 PvE mode will feature four connected runs with progression carrying between them.
- Perimeter reportedly gains a massive underground section and up to four boss encounters.
- A new Flash Boost system could let players create increasingly powerful temporary builds.
- New weapons, Sponsored Kit upgrades, vendor changes, Ranked updates, and cosmetics are reportedly being tested.
Marathon Season 3 PvE Mode Reportedly Features Four Runs
According to information reportedly taken from a Season 3 playtest, the new PvE activity consists of four linked runs. Players can apparently choose maps during the first three, complete PvE objectives, gather resources, improve their builds, and increase their overall score.
The fourth run reportedly takes everyone to the redesigned Perimeter, where players must face the Tick Queen. The combined score accumulated throughout all four runs is said to determine the final reward tier.
The concept appears to expand upon Vault Breaker, Bungie’s experimental Season 2 PvE mode. Vault Breaker already introduced multi-run progression, Sponsored Kits, and increasingly difficult PvE encounters, with Bungie explicitly describing it as a testbed for the full PvE mode coming in Season 3.
Perimeter Could Receive a Massive Underground Expansion
One of the biggest leaked changes involves Perimeter. The redesigned map reportedly includes an underground area roughly comparable in size to its existing above-ground section.
Bungie has confirmed that Perimeter is being revamped with major new areas, encounters, and gameplay, although the size and underground layout mentioned in the leak have not been officially announced.
The leak claims players could encounter four major bosses:
- Compiler, which can reportedly appear while exploring Perimeter
- Modified Locus, an unofficial nickname for a large Locus-type enemy featuring multiple shields and missile attacks
- Tick Queen, reportedly the guaranteed final boss of the fourth PvE run
- Mystery Boss, an encounter whose activation requirements remain unknown
The Tick Queen battle is reportedly completely cooperative, with players fighting AI enemies rather than rival Runners. Its mechanics allegedly involve collecting fuel from enemies, activating machinery, reaching safe areas during timed phases, and returning to damage the boss.
Flash Boosts Could Completely Change PvE Builds
Season 3 is also reportedly testing a new system called Flash Boosts. Players can allegedly equip up to six boosts and reroll them while progressing through rarity levels ranging from White through Blue, Purple, Gold, and Red. Certain Flash Boosts may also be exclusive to particular Runner shells.
Examples reportedly tested include boosts that restore ability energy when using Shield Batteries, improve pistol performance when enemies are nearby, and cause EMP kills to chain electricity between nearby targets.
Sponsored Kits may also become upgradeable, while vendors and faction kit systems are reportedly being reworked.
New Marathon Season 3 Weapons Also Leak
Several unreleased weapons and items were mentioned in the leak. A weapon called the V17 reportedly has some form of fire-based attack, although it is currently unclear exactly how it functions. A throwing knife is also allegedly being tested, alongside an unfinished revolver.
Bungie has independently confirmed that Season 3 will introduce new weapons and equipment, but it has not announced these specific items.
Season 3 Looks Like a Major Expansion of Marathon’s PvE Side
Other leaked details point toward changes to Ranked, new weapon skins, Runner cosmetics, vendor progression, Sponsored Kits, and the wider progression system.
Bungie has already said it wants Marathon to become less grindy while expanding progression systems and experimenting with PvE, PvP, and PvP-lite experiences.
As of writing, the safest conclusion is that the September 22 Season 3 launch, full PvE mode, Perimeter revamp, new Runner shell, weapons, and equipment are confirmed. The four-run structure, bosses, underground expansion, Flash Boosts, V17, throwing knives, and other detailed systems come from leaks and should be treated as subject to change until Bungie officially reveals Season 3.
