Backpack

Nothing is more embarrassing for an adventurer than to find the big treasure and then being unable to take the masses of coins with them. And it is downright lethal to go adventuring without carrying equipment.

For these situations, a backpack is very useful. Worn on the back, it does not hinder the adventurer in any way, but allows transportation of numerous items without problem. It therefore is absolutely essential for every adventurer to have one, otherwise he or she shouldn't even bother with leaving town. They appear in Ultima VI, Ultima Underworld, Ultima VII, Ultima Underworld II and Ultima VII Part Two.

Description
Backpacks were first available in Ultima VI, although during that time they were only used as a way to have extra space to carry more things. However, starting with Ultima Underworld, having a backpack became critical, even more so in later games. From Ultima VIII onwards, the backpack became part of the interface and could no longer be un-equipped.

Trivia

 * In Ultima IX, Blackthorn takes away the Avatar's backpack at one time of the game. The game progress is seriously hindered by this, and once the player gets it back, it has turned into a complete mess.
 * From Ultima VII onward, size and mass of an item were important. This was only changed in Ultima IX.