Storage Deck Upgrade

A Storage Deck Upgrade (or SDU) is an upgrade item that can be applied to a character's inventory to increase that character's storage capacity. The different types of SDU that players will interact with include a Backpack SDU and a number of different weapon SDU's. Another class of SDU is referred to as a "Weapon Slot Storage Deck" is automatically applied to a character without the need for player interaction.

Backpack SDU
The Backpack SDU's each offer 3 additional slots of storage capacity. Each one is gained as a reward for completing one of the ten Claptrap Rescue Missions, for an extra thirty spaces of storage that can be earned throughout the game to a total capacity of 42 on the first playthrough. Once players complete the story on a first playthrough the higher difficulty second playthrough will allow them to repeat the Claptrap Rescue Missions for more Backpack SDU's. Unlike the first playthrough, only the first five of these quests seem to offer a chance of getting an extra SDU when completed. This can take several tries from either exiting without saving or loading from a backup file due to the SDU reward not being 100%. The original total maximum inventory slots is 57 on the game disc alone, but with the release of the "Dr.Ned's Zombie Island" DLC including an additional Claptrap to save, the new maximum is 63. You can receive the two extra upgrades by accessing the DLC from each main game playthrough (one per playthrough).

Weapon Slot Storage Deck
Two Weapon Slot SDU's are available as quest rewards. These increase the weapon equipping capacity of a character by two additional weapons, allowing an improved selection of weapons in the thick of a fire fight. The two quests that offer these as rewards are:


 * Return To Zed
 * Road Warriors: Bandit Apocalypse

Weapon SDU's
Eight other SDU types that players interact with are SDU's for increasing a character's ammunition storage. These SDU's are purchased from Ammo Vendors and have quality levels that increase in the same manner as weapon quality, indicated by colour. Characters gradually unlock higher quality weapon SDU's as they increase in level and progress through the game. The higher the quality, the greater the capacity and the higher the cost.

These do not have to be bought in order as they appear in game. If you buy a higher capacity SDU before a previous one, it will jump up to the higher one. In essence this makes buying only Dark Oranges the most cost effective way to upgrade.