System Guide
Runner Shells
MARATHON · UPDATED JUNE 2026 · TIERLISTHQ
Runner Shells are Marathon's class system. Each Shell defines your abilities, your role in a squad, and your approach to extraction. Unlike a traditional class lock, every Shell is available to every player from day one — you switch between runs freely at the Shell select screen.
Ability Structure
Every Runner Shell has three defined ability slots. The structure is identical across all shells — what differs is what those abilities do.
Prime Ability
Your primary active ability. Typically your highest-impact tool with the longest cooldown. Prime abilities define what role a shell plays — Triage's Reboot+, Assassin's invisibility, Sentinel's Defender System.
Tactical Ability
Your secondary active ability. Lower cooldown, more situational use. Designed to complement the Prime — Sentinel's Snare Mine, Assassin's smoke grenade, Triage's Med-Drone.
Traits
Passive or conditional abilities that modify your playstyle. Each shell has two Traits. Some Traits, like Triage's Battery Overcharge, can fundamentally change how you play the shell by enabling unexpected aggressive options.
Switching Shells
Shell switching happens at the Shell select screen between extraction runs. There is no mid-match shell change. This means your Shell choice is a pre-run decision — pick based on the map you're queuing into, your squad composition, and your goal for the run.
Shell switching and The Cradle
Season 2's Cradle progression system is built around Energy and stat points — not shell-specific progression. Stat points benefit any shell you play. Switching shells does not reset your Cradle investment. This makes shell experimentation more viable than in Season 1.
The Eight Shells
Assassin
Stealth flanker. Smoke and invisibility. Best solo shell in Season 2. High learning curve.
Recon
Intel scout. Scanning abilities that reveal enemy positions. Best squad shell for information control.
Triage
Squad medic. Med-Drone heals, Reboot+ full revives. Essential in any coordinated squad.
Sentinel
Territory anchor. Snare Mines and Defender System. Space control specialist. Season 2 new shell.
Thief
Mobile looter. High mobility, extraction-focused kit. Strong solo pick and Sentinel counter.
Vandal
Chaos aggressor. Highest movement ceiling. Highest skill requirement. Built for mechanical players.
Destroyer
Combat specialist. Simple, direct, forgiving. Best beginner pick after Rook.
Rook
Beginner frame. Operates under different rules. Designed specifically to teach Marathon's systems.
How to Choose Your Shell
Three factors determine the right shell for a run: your playstyle, your squad composition, and your target map. If you play solo, prioritise shells with self-sufficient kits — Assassin, Thief, or Rook. If you play in a coordinated squad, Recon and Triage provide the most structural value. On Night Marsh specifically, Sentinel and Recon gain additional value from the darkness mechanic.