In the equipment section of the D&D basic rules, it lists "light" as a weapon property of the hand crossbow.
The "light" property offers the following attributes:
Light. A light weapon is small and easy to handle, making it ideal for use when fighting with two weapons. See the rules for two-weapon fighting in chapter 9.
So, this would mean I can use my hand crossbow in two weapon fighting... Great! However, in the TWF rules in chapter 9 it says the following:
When you take the Attack action and attack with a light melee weapon that you’re holding in one hand, you can use a bonus action to attack with a different light melee weapon that you’re holding in the other hand.
Two weapon fighting only applies to melee weapons! Why does the hand crossbow have the light property? What purpose is it serving?
Now with the addition of the Feats in the players handbook my question still remains. The feat for crossbow expert says the following:
Thanks to extensive practice with the crossbow, you gain the following benefits:
- You ignore the loading quality of crossbows with which you are proficient.
- Being within 5 feet of a hostile creature doesn't impose disadvantage on your ranged attacked rolls.
- When you use the Attack action and you attack with a one-handed weapon, you can use a bonus action to attack with a loaded hand crossbow you are holding.
As you can see the feat replaces the Two weapon fighting rules, and so the light keyword is still not needed.