Carrying capacity

All items in DDO have weight. The amount of weight a character can hold at maximum is represented by a bar at the bottom of the inventory screen labeled Load. As the bar slowly fills from Load: Light to Load: Medium, and Load: Heavy the character's speed and ability to perform certain actions is hindered.

The amount a player can carry (weight wise) is governed by his strength, and race (halflings have 3/4 the maximum carrying capacity of other races with the same strength). The higher his strength, the more a character can carry. Note this is not strength modifier, so increasing your strength to an odd number does increase your carrying capacity even though your strength modifier remains the same. Most players will want to keep their load below Medium (33% load) as most detrimental effects occur after Medium Encumbrance. Heavy (66% load) will greatly slow character speed, and after heavy encumbrance one becomes overburdened and very slow to act.

This lists the confirmed carrying capacities based on strength. It also has at what point you reach Medium Encumbrance and Heavy Encumbrance (aka Burdened)
 * Load: Light (0% to 33.33% load): no penalties.
 * Load: Medium (33.34% to 66.66% load): reduces Run speed by 4.3%, caps your maximum dexterity bonus at 3, and gives you a -3 armor check penalty. Monk characters become un-centered.
 * Load: Heavy (66.67% to 100% load): reduces Run speed by 11.8%, caps your maximum dexterity bonus at 1, and gives you a -6 armor check penalty. You are given the Burdened status ("You're burdened.").
 * Load: Other (more than 100% load): reduces Run speed by 30.8%, caps your maximum dexterity bonus at 1, and gives you a -6 armor check penalty. You are given the Overloaded status ("You're overloaded!").