Each weapon confers a number of abilities onto the warrior wielding it. This will sometimes be a bonus to their characteristic profile or perhaps grant the wielder one or more special rules, as detailed in the weapon's rules.
Each weapon has its own characteristic profile. There are three sections to a weapon's profile: Range, Strength and Special Rules.
The range tells you at what distance the weapon can be used. If a weapon's range is 'combat' then it can only be used in close combat. If the range is a number of some kind, it is a missile weapon and the number is its maximum range.
A weapon's Strength can take three forms. If the Strength is shown as a modifier, for example +1, then this is the modifier the weapon applies to the wielding model's strength. If a weapon's Strength is shown as 'as user' then attacks made with the weapon use the wielder's own unmodified Strength. Alternatively, if a weapon has a fixed Strength, then all attacks made with that weapon use the Strength value shown – the wielder's Strength is ignored.
Many weapons confer special abilities on the attacks made by the wielder. Sometimes the special rule will be explained immediately after the weapon profile. Otherwise, details on these special rules can be found in the chapter of the same name. Any bonuses applied from a model’s equipment only has an effect in the phases they are actually used. Note that any characteristics bonuses from weapons normally apply when the model actually attacks – they cannot be used for characteristics tests or spell effects etc. When a weapon does not say when the characteristic bonus applies, then it only applies when striking, or being struck, in close combat.