Melee Attacks
With a melee weapon, you can strike any opponent in a square adjacent to your space. You add your Strength modifier to your melee attack rolls and to your melee damage rolls.
Some melee weapons in Chapter 7 have the reach special property, as indicated in their descriptions, and some monsters have natural reach. Typically, a character or monster with reach can attack any foe within their reach (see Reach and Threatened Squares on page 255 for more details).
Source
Core Rulebook pg. 244
