Editing 4SRD:Basics (section)

==DAMAGE==
When your attack succeeds, you deal damage. The type of weapon used determines the amount of damage you deal. Effects that modify weapon damage apply to unarmed strikes and the natural physical attack forms of creatures.
Damage reduces a target’s current hit points.<br>
Minimum Damage: If penalties reduce the damage result to less than 1, a hit still deals 1 point of damage.<br>
Strength Bonus: When you hit with a melee or thrown weapon add your Strength modifier to the damage result.*<br>
Multiplying Damage: Sometimes you multiply the damage on the dice by some factor, such as for specific powers. Roll the dice multiple times and total the results. Add the bonuses to the rolled damage afterward. You do not add bonuses from Abilities, Feats, Enhancements or other sources multiple times.*<br>