Pack Rat

Pack Rat is a perk in Fallout 2, Fallout: New Vegas, Fallout 76 and Fallout Tactics.

Effects
This perk increases one's carry weight by 50 lbs.

You are efficient at arranging your inventory in general. This makes it much easier to carry that little extra you've always needed. This is useful for characters with low Strength, i.e. sharpshooters and mediators.

Its usefulness is reduced in Fallout 2 with the addition of larger teams of traveling companions and the Highwayman's trunk.

Effects
This perk halves the carry weight of items that have a carry weight of 2 or less.

In hardcore mode, this applies to ammunition weight, which could cause this perk to be especially useful, allowing you to carry twice as much ammunition at the same weight. Note that with this perk, all affected items in the game world will display their new, lower weight whether or not they are in your inventory. (This does not change companion carrying capacity—they still carry these items at full weight.)