A Large Rucksack, or backpack, is necessary in the Zombies mode for Call of Duty: Modern Warfare 3 to simply carry more stuff on your character. There are plenty of items and schematics to pick up, so it is best to be prepared with more portable storage.
How to Get a Large Rucksack in Modern Warfare 3 Zombies
There are two ways to get a Large Rucksack in the Zombies mode: getting the item as a reward for completing contracts and purchasing it from the Buy Station. One requires a lot of luck, while the other requires better gear and weapons before tackling.
Getting a Large Rucksack as a reward for completing various contracts is possible, but it can be pretty random, and the chances are not great. Completing contracts in the orange and red threat zones could yield a higher chance of getting it, but it is not guaranteed.
The other option is to buy the Large Rucksack from the Buy Station, but it is only available at the Buy Stations located in the red threat zone. This is the highest difficulty for enemies on the map, and should come equipped with Pack-a-Punch upgraded guns and more armor.
A lot of Essence, or in-game currency, is also required. The Large Rucksack costs 10,000 Essence to purchase.
It is a lot of money to gear up to survive the red zone and purchase the giant backpack, but players will get to keep the storage as long as they exfil out of the game and do not die completely. It is worth the risk to be able to carry nine items at one time.
For more Call of Duty: Modern Warfare 3 Zombies coverage, please check out our guide on how to get Ammo Mod Circuit Boards.