When using a weapon to make an attack, you roll a d20 and add a bonus that depends on the weapon you are using (Strength modifier for melee weapons and Dexterity modifier for ranged weapons). If you are proficient in the weapon, you also add your proficiency bonus to the attack roll. If the number rolled meets or exceeds the targets Armor Class (AC), the attack hits. A hit creature takes damage of an amount and type determined by the weapon used in the attack. For the damage you also add the modifier of the ability used to make the attack.

A duelist lunges for his opponent’s neck, a raging berserker swings his axe around his head before bringing it down with tremendous force. Whenever your character aims for a vital point or swings with all the momentum of their weapon, that is represented by them making a Power Attack. 

When you make an attack with a weapon in which you are Proficient, unless otherwise specified, you can choose to perform a Power Attack by removing your Proficiency Bonus from the attack roll to add twice your Proficiency Bonus to the damage roll. 

When making an attack with a finesse weapon, you use your choice of your Strength or Dexterity modifier for the attack and damage rolls. You must use the same modifier for both rolls. 

You cannot stow this weapon as part of the Attack Action. 

Once on each of your turns when you make the attack action, and attack with a weapon you are holding, you can use a bonus action to attack with a Light weapon you are holding in another hand. You don’t add your ability modifier to the extra attack’s damage unless that modifier is negative. 

This weapon emits a thunderous boom audible out to 300 feet. 

If this weapon is submerged in water, it can not be fired one hour. Alternatively, you can spend one minute cleaning the weapon.

A weapon that can be used to make a ranged attack has a range shown in parentheses above it's properties or as part of the thrown property. The range lists two numbers. The first is the weapon’s normal range in feet, and the second indicates the weapon’s long range. When attacking a target beyond normal range, you have disadvantage on the attack roll. You can’t attack a target beyond the weapon’s long range, and as normal, ranged attacks made against creatures within 5 ft of you are made at disadvantage.

This weapon adds 5 feet to your reach when you attack with it, as well as when determining your reach for opportunity attacks with it. 

Some weapons have what's known as a "Special" weapon property. Special properties are weapon properties that alter how the weapon functions.

If a weapon has the thrown property, you can throw the weapon to make a ranged attack. If the weapon is a melee weapon, you use the same ability modifier for that attack roll and damage roll that you would use for a melee attack with the weapon. For example, if you throw a handaxe, you use your Strength, but if you throw a dagger, you can use either your Strength or your Dexterity, since the dagger has the finesse property. 

This weapon requires two hands when you attack with it. This property is relevant only when you attack with the weapon, not when you simply hold it. 

This weapon can be used with one or two hands. A damage value in parentheses appears with the property — the damage when the weapon is used with two hands to make a melee attack.