Marathon Guide | How to Increase Vault Size

Here’s a guide on how to increase Vault Size in Marathon.

Game Guide by Ragib Rawnak on Mar 06, 2026

The Vault is where you store your Loot, Resources, and Ammo. It holds everything from basic items to rare Prestige gear. You will likely find that you run out of room fast when you first start. This guide explains how to add more rows so you can keep more of what you find.

Expanding Your Space

You can get more room in your Vault by buying Upgrades. You need to look for the Expansion tasks from the CyberAcme group in Marathon.

Each level of Expansion adds rows to your storage. You should try to get these first because rare items take up a lot of space.

Marathon, Guide, How to Increase Vault Size

Expansion Levels

There are five levels of Expansion you can buy in Marathon. Each one costs Credits and materials like Unstable Diode and Unstable Gunmetal.

You also need a high enough rank with CyberAcme. Expansion Level 1 gives 8 rows and requires rank 3, 2,500 Credits, and 12 Unstable Diode. The second level of expansion adds 8 rows, 4,000 credits, 22 unstable diodes, and 12 unstable gunmetals. It costs rank 7.

Expansion Level 3 adds 6 rows at rank 12 for 5,000 Credits, 27 Unstable Diode, and 15 Unstable Gunmetal.

Expansion Level 4 gives 4 rows for rank 18, 7,000 Credits, 30 Unstable Diode, and 18 Unstable Gunmetal. Expansion Level 5 adds 4 rows at rank 28 for 10,000 Credits, 50 Unstable Diode, and 30 Unstable Gunmetal.

Marathon, Guide, How to Increase Vault Size

Finding Materials

You can find Unstable Diode and Unstable Gunmetal in most places on the map. You should check inside buildings to find them easily. These Upgrades only stay for the current season. When the Seasonal Wipe happens, you must unlock the extra space again.

Also, check our Marathon Review and other guides below