See also: Character Combat
A creature or object with Damage Reduction (DR) ignores a certain amount of Damage every Attack. The amount of Damage it ignores is always indicated; for example, an object with DR 10 ignores the first 10 points of Damage from each Attack.
Damage Reduction is sometimes bypassed by one or more specific Damage Types (Noted after the DR value). For example, a creature with DR 5/Energy ignores 5 points of Damage from any source except one that deals Energy Damage (Such as from a blaster). Similarly, a creature with DR 10/Piercing or Slashing ignores 10 points of Damage from any source except one that deals Piercing or Slashing Damage.
Certain Talents grant Damage Reduction. When a character with multiple types of Damage Reduction takes Damage, use whichever Damage Reduction value most benefits the character, based on the type of Damage. For example, if a character with DR 1 and DR 10/Energy is struck by a blaster, it's better for the character to apply their DR 1 against the attack (Since DR 10/Energy is bypassed by a blaster).
Lightsabers ignore Damage Reduction unless specifically noted otherwise.