Carrying Capacity and Encumbrance

While a character's equipment and armor can be crucial to their survival when adventuring, too much of either can serve to hinder their mobility and agility. This hinderance can depend on several factors, and takes the form of encumbrance, as detailed below.
Carrying capacity determines how much a character’s equipment slows him down. Encumbrance comes in two parts: encumbrance by armor and encumbrance by total weight.

Encumbrance

A character's encumbrance comes in two forms, encumbrance caused by armor and encumbrance caused by weight. While not mechanically described here, encumbrance can be caused by the bulk of items carried rather than weight can factor in as well, though such encumbrance is determined by the DM on a case-by-case basis. Encumbrance from multiple sources do not stack: only the most severe penalties take effect.
Encumbrance affects a character in four ways: maximum Dexterity bonus to Armor Class, armor check penalty, speed, and running speed.

• Maximum Dexterity Bonus represents the maximum that your Dexterity score can contribute to your armor class. If your modifier is lower than this, it has no effect.
• Armor Check Penalty is a modifier applied to any skills you attempt that are impacted by an armor check penalty. Which skills this applies to and how it applies are detailed in the Character Skills article.
• Speed is reduced for most characters when they wear medium or heavy armor, or suffer from a medium or heavy load.
• Running Speed is a multiplier to speed that is applied when a character takes the Run action. This multiplier is x4 by default for most characters, but can be reduced or negated by heavier armor or loads.

Encumbrance by Armor

A character’s armor and shield have their encumbrance effects listed in the stats of each piece. Unlike most other encumbrance effects, the armor check penalty from a carried shield stacks with the penalty from worn armor.

Encumbrance by Weight

A character's carrying capacity is primarily determined by their strength, as detailed in the carrying capacity table. A character's size can modify these values, as can some racial characteristics and other character traits.
A character with more than a light load is encumbered by the weight of their carried gear, as listed in the encumbrance effects table. For the purposes of abilities or skills that are restricted by armor, a medium or heavy load counts as wearing medium or heavy armor. As stated above, encumbrance from weight does not stack with encumbrance from armor, and only the most severe of each penalty is applied.

Lifting and Dragging: A character can lift as much as their maximum load over their head. A character’s maximum load is the highest amount of weight listed for a character’s Strength in the heavy load column of Table: Carrying Capacity.
A character can lift as much as double their maximum load off the ground, but they can only stagger around with it. While overloaded in this way, the character loses any Dexterity bonus to AC and can move only 5 feet per round (as a Full-Round Action).
A character can generally push or drag along the ground as much as five times their maximum load. Favorable conditions can double these numbers, and bad circumstances can reduce them by half or more.
Bigger and Smaller Creatures: The figures on Table: Carrying Capacity are for Medium bipedal creatures. A larger bipedal creature can carry more weight depending on its size category, as follows: Large ×2, Huge ×4, Gargantuan ×8, Colossal ×16. A smaller creature can carry less weight depending on its size category, as follows: Small ×3/4, Tiny ×1/2, Diminutive ×1/4, Fine ×1/8.
Quadrupeds can carry heavier loads than bipeds can. Multiply the values corresponding to the creature’s Strength score from Table: Carrying Capacity by the appropriate modifier, as follows: Fine ×1/4, Diminutive ×1/2, Tiny ×3/4, Small ×1, Medium ×1-1/2, Large ×3, Huge ×6, Gargantuan ×12, Colossal ×24.
Tremendous Strength: For Strength scores not shown on Table: Carrying Capacity, find the Strength score between 20 and 29 that has the same number in the “ones” digit as the creature’s Strength score does and multiply the numbers in that row by 4 for every 10 points the creature’s Strength is above the score for that row.