If a character is encumbered, the character's movement rate will be affected depending on the degree of encumbrance. Lightly-encumbered characters will no longer run and will move at 100% of their base speed at walking pace. If combined with detect mode or stealth mode base speed is reduced to 50%. If character is in detect mode, stealth mode and lightly-encumbered base speed is reduced to 25%. Heavy-encumbrance means the character's movement speed is reduced still further by an additional 50%
Drinking potions of bull's strength, casting the spell Bull's strength, using the Blackguard feat Bull's Strength and/or wearing items which grant bonuses to strength can keep a character at regular running speed briefly before returning to sell surplus items.