Marathon: Runner Shells – All Shells, Cores, Implants & Rook Mode

• In Marathon, you don’t play as a fragile human soldier. You inhabit a Runner Shell… a biosynthetic body designed for high-risk operations on Tau Ceti IV.
• Your consciousness transfers into these shells, allowing you to enter dangerous combat zones without permanent death. Each shell is built around a specific gameplay archetype, giving it a natural lean toward roles like intel gathering, disruption, mobility, or combat support.
• Shells have distinct silhouettes, making it easier to identify threats in the field and quickly assess how an opponent might engage.
• Runner Shells are modular platforms designed for customization.

HOW CUSTOMIZATION WORKS

• Every run begins with decisions.
• You tailor your shell’s playstyle through a combination of:
  • Cores
  • Implants
  • Weapons
  • Mods
• These systems allow you to adjust movement, survivability, utility, and combat effectiveness.
• Bungie describes this as building around a shell’s “natural strengths” rather than replacing them entirely.
• This creates flexibility: the same shell can feel very different depending on your loadout.

CORES VS IMPLANTS

• Customization in Marathon centers around two major systems: 

CORE

• Cores are generally shell-specific enhancements.
• They modify or strengthen a shell’s inherent abilities.
• For example, Bungie highlights the Thief shell using cores to:
  • Improve survivability
  • Reduce ability cooldowns
  • Enhance infiltration capabilities
  • Cores reinforce identity.

IMPLANTS

• Implants are more universal…any shell can equip them!
• Implants:
  • Grant stat bonuses
  • Include a random perk
  • Higher-tier implants add an additional fixed perk
• Bungie uses the example of a high-tier implant called Ping+ V5, which boosts the Recon shell’s Echo Pulse ability while also granting an extra perk.
• Implants expand possibility across shells.

RUNNER SHELL BREAKDOWN

• Here is a list and general details surrounding every runner shell that we know so far:

DESTROYER

Archetype: Combat Specialist

• The Destroyer is built for frontline engagements.
  • It emphasizes durability and sustained combat presence.
• This shell appears designed to anchor fights and control space.

Toolkit

• A deployable Riot Barricade
• Shoulder mounted heat-seeking missile pods
• Thrusters for movement and positioning

ASSASSIN

Archetype: SHADOW AGENT

• The Assassin leans into stealth and tactical engagement.
• The focus is on repositioning, surprise, and eliminating targets before they can respond.

Toolkit

• Smoke deployment

• Camouflage technology

RECON

Archetype: INTEL SPECIALIST

• Recon shells are information machines.
• This shell helps teams anticipate movement and detect threats before direct contact.

Toolkit

• Echo Pulse scanning
• Tracker drones
• Holographic footstep trails

VANDAL

Archetype: Combat Anarchist

• The Vandal emphasizes high mobility and disruption.
• This shell rewards aggression and creative traversal.

Toolkit

• Two build directions:
  • A mobility-focused build:
    • Increased movement speed
    • Jump height enhancements
    • Heat capacity adjustments
    • Double-to-triple jump upgrades
  • A chaos-oriented build:
    • Arm cannon that propels the Vandal
    • Area-of-effect slam
    • No fall damage

THIEF

Archetype: Covert Acquisition

• The Thief excels at infiltration and objective manipulation.
• The Thief is built to move quickly, scout safely, and extract efficiently.

Toolkit

• Enhanced visors
• A piloted butterfly drone
• Grappling capabilities

TRIAGE

Archetype: Field Medic

• Triage supports allies through recovery and enhancement.
• This shell appears designed for team sustain and mid-fight stabilization.

Toolkit

• Healing drones
• Reboot functionality
• Combat buffs

SCAVENGER: ROOK

Archetype: SCAVENGER FRAME

• Rook is a unique shell designed specifically for Scavenger Mode.
• Unlike other shells, Rook:
  • Enters a match already in progress
  • Drops in solo
  • Starts with no loadout
  • Risks nothing upon entry

NOTES

• This shell offers a lower-risk, opportunistic playstyle.
  • It allows players to enter an active environment, gather resources, and exit without committing a pre-built kit.
• Rook represents a different rhythm of play… reactive, adaptive, and opportunistic.