Combat Points are required to buy items from a Weapon Depot. Combat Points can be gained by killing enemy agents, performing map objectives, or earning morale boosts. Weapon depots can be found easily by scanning the map with HRV active. Interact with a Weapon Depot by approaching it and hitting the "E" key.

Scroll through the Weapon Depot's contents with the A or D key. Pressing the spacebar will purchase the currently selected item. Once purchased, this item will take over the secondary weapon slot on your agent. Be warned - these weapons are lost on death, so make them count. Only five weapons can be set as a Weapon Depot's inventory. Purchase new heavy weapons and stock them into a depot by visiting the customization screen.