[RPG] mechanical benefit to using a light crossbow over a long bow or short bow


A longbow (1d8, 150/600 range), and a shortbow (1d6, 80/320 range) benefit from "Extra Attack".

A light crossbow (1d8, 80/320 range), or a hand crossbow (1d6, 30/120 range), do not benefit from "Extra Attack".

A light crossbow is worse in terms of range, and damage (with Extra Attack) than the longbow. A light crossbow is on par for range with the shortbow, and worse for damage (with Extra Attack).

I understand that with Crossbow Expert Feat, you can make 3 attacks with hand crossbows at still a very short range of 30 feet.

Mechanically, I don't see any benefit to a light crossbow if you have an Extra Attack. Is there some benefit to using a light crossbow I am missing?

Best Answer

Lack of martial weapon proficiency

Just by their stats, a longbow does seem strictly better than a light crossbow.

However, longbows are martial weapons, and light crossbows are simple weapons. (PHB, p. 149)

As a result, some classes/races will not be able to use longbows effectively due to their lack of proficiency with martial weapons - in particular classes without Extra Attack often lack martial weapon proficiency.

As an example, a Human Rogue cannot wield a longbow with proficiency (barring feats). For this character, a light crossbow is one damage die better than a shortbow (which is also a simple weapon). Since they are a Rogue, they do not get Extra Attack, and so the fact that the shortbow can benefit from Extra Attack while the crossbow cannot (Loading property) does not come into play.

It's worth noting that a character who does have martial weapon proficiencies will likely be choosing between a heavy crossbow (which does more damage per attack) and a longbow (which works with Extra attack).

Underwater combat

Crossbows are better weapons than longbows underwater, due to their lack of disadvantage.

From the rules on underwater combat (PHB p.198):

A ranged weapon attack automatically misses a target beyond the weapon’s normal range. Even against a target within normal range, the attack roll has disadvantage unless the weapon is a crossbow, a net, or a weapon that is thrown like a javelin (including a spear, trident, or dart).

Small characters

Longbows and heavy crossbows both possess the Heavy property:

Small creatures have disadvantage on Attack rolls with heavy Weapons. A heavy weapon’s size and bulk make it too large for a Small creature to use effectively.

As a result, small characters will not want to use this kind of weapon, and would choose a shortbow or light crossbow (depending on their class, as above) instead.