Inappropriately sized crossbows

[Dairfaron]

Since crossbows don't get a lot of love and are regarded as subpar by most players, you don't find much about them concerning rules questions.
So, there's this issue I couldn't quite wrap my head around. While BOWS explicitly call out always needing two hands to fire, regardless of size, crossbows do not. In fact, most crossbows explicitly call out being able to be fired one-handedly, albeit with some penalties.
Of course, you will always need two hands to reload a crossbow, regardless of size (unless you have certain magic weapon special abilities), as reloading a crossbow with one hand would be as unrealistic as reloading a longbow with one hand. This is why we will focus on the handedness for FIRING here.

In the end it can be boiled down to four different crossbow types (repeating crossbows generally work like crossbows of their respective sizes when it comes to firing):

Hand, Light, Heavy and Double

Now, a light crossbow counts as a light weapon for TWF, while a heavy crossbow counts as one-handed for the same purpose.
Hand crossbows are still light weapons but they don't incur the -2- penalty for one-handed shooting, as they are specifically designed for it. The exact opposite is true for the double crossbow, which is simply too unwieldy to be shot with one hand and even incurs large penalties for normal welding.

Now what happens when we change sizes?
While the standard classification into light, one-handed and two-handed weapons is made for melee weapons, the language in the different crossbow descriptions heavily implies that the same rules can roughly be applied to crossbows. This entire post is based on the assumption that this is the case, so it is much more of a RAI thing than a RAW thing.

My assumption would be:

Hand Crossbow: large==one-handed, huge==two-handed?
Light Crossbow: same as above

As both are already light weapons, you couldn't make them smaller without losing the ability to shoot them (realistically that's debatable, though. There are those really small toothpick crossbows you can buy, that are, like, diminutive size). Making them larger also wouldn't make that much sense in terms of optimization.

Heavy Crossbow: small==light weapon, large==two-handed?

So you could shoot a large heavy crossbow with two hands possibly at the same penalties you incur when firing it with one hand. 2d8 damage sounds nice if you want to go for a ranged vital strike sniper build.

Double Crossbow: small==one-handed, tiny==light weapon?

Now this is funky, since the double crossbow doesn't mention at all that it can be shot one-handedly. And why should it mention it? (this is a rhetorical question) It is designed as a two-handed weapon, so that there is no need for such language if wielder and/or weapon are neither over- nor undersized. Thus, the fact that it has no language for one-handed wielding should not mean it can't be wielded in one hand if it's small enough (albeit at significant penalties). It has literally the same penalties as a large heavy crossbow (-4 to hit with two hands) and deals the exact same damage (2d8, but with two bolts instead of one). So reducing it by one size should enable it to be fired one-handedly at a -4 penalty plus the -2 from being undersized.

Feel free to chime in with your opinions! (As I said in the introduction, this is more about the RAI aspect of the subject)

[Meirril]

Messing with the size of a crossbow doesn't really make sense. You're introducing an extra -2 penalty to hit for every size category, and the number of hands required is questionable.

I think its better to question the fundamentals of crossbows. After all, Pathfinder crossbows don't reflect real crossbows at all. Well, other than being simple weapons instead of martial.

Like there is the whole strength thing. You can buy a bow that matches your strength at incredible cost. You can't get a crossbow at your strength...which makes no sense when you look at actual crossbows and you realize they have several different machines that assist the user into pulling a bow that they couldn't do by hand.

Sure, you can make a crossbow that you can span by hand, pulling the bow with your fingers. That is the fastest method of using a non-repeating crossbow. But other spanning devices let you pull heavier bows by using simple machines to increase your effective strength.

A prod is a simple lever that may or may not be attached to the crossbow. There are also crank models that let you use a series of gears to pull a bow that is much more powerful (and dangerous).

Different sorts of crossbows should have different effects from using such methods. Hand crossbows shouldn't have such a loading device. The purpose behind them is a hidden weapon that loads and fires quickly.

Light crossbows shouldn't be quite as powerful as heavy crossbows, but should benefit from high user strength. As such, a normal light crossbow is made at 10 str, but Masterwork Light Crossbows can be made at any strength. The MC Light Crossbow adds str mod to damage. Using a crossbow made for a higher strength shouldn't be possible, while a lower strength has no benefit or penalty.

Heavy Crossbows should be high damage weapons. As such, they have the same properties as Light Crossbows above, except MC Heavy Crossbows provide a bonus to damage equal to (str-10). This is approximately double the str mod.

Double Crossbows should be treated as two light crossbows combined into a single weapon, not two heavy crossbows. Any modification done to a Double Crossbow treats it as a double weapon and a light crossbow.

A Prod can be added to any light or heavy crossbow, for a cost of 10g. This adds +2 str for damage calculations, and increases the reload time by 1 increment.

Crossbow loading increment pattern: free -> swift -> move -> standard -> full round -> 2 full round -> +1 full round.

A Crank can be added to any light or heavy crossbow, for a cost of 50g. This adds +4 str for damage calculations, and increases the reload time by 2 increments.

A new weapon enchantment special ability should be created called Spanning. Spanning 1 lowers the time to reload the Crossbow by 1 increment, as a +1 equivalent. Spanning can be made from 1 to 5 with an equal cost in enhancement bonus, for an equal amount of loading increment reductions.

Repeating Crossbows are flimsy constructions that are meant to work off of a mechanical principle. As such they are made at 10 strength and no modification is possible.

I think the above modifications should entice a few players to try crossbows, without making them better the bows.

[Meirril]

Oh, and if you purchased a MC crossbow for your 14 str character it should be recorded like this:

MC Heavy Crossbow (14 str), w/Prod. 1d10+6 damage, reload: 2 full rounds. market value: 360gp.

[LordKailas]

I'm not sure that RAI even comes in to play. Lets see what happens if we apply the rules as they currently stand.

-----------------------------
Hand Crossbow(medium)
Dmg: 1d4 (avg 2.5)
Penalty to hit one handed (medium creature): 0

Hand Crossbow(Large)
Dmg: 1d6 (avg 3.5)
Penalty to hit two handed (medium creature): -2
-----------------------------
Light Crossbow(medium)
Dmg: 1d8 (avg 4.5)
Penalty to hit one handed (medium creature): -2

Light Crossbow(Large)
Dmg: 2d6 (avg 7)
Penalty to hit two handed (medium creature): -4
-----------------------------
Heavy Crossbow(medium)
Dmg: 1d10 (avg 5.5)
Penalty to hit one handed (medium creature): -4

Heavy Crossbow(Large)
Dmg: 2d8 (avg 9)
Penalty to hit two handed (medium creature): -6
-----------------------------
Double Crossbow(medium)
Dmg: 2d8 (avg 9)
Penalty to hit two handed (medium creature): -4

Double Crossbow(small)
Dmg: 2d6 (avg 7)
Penalty to hit two handed (medium creature): -4
Penalty to hit one handed (medium creature): -6
-----------------------------
The small double crossbow is a pure extrapolation. I've treated the double crossbow as being the same as dual wielding a pair of light crossbows. So, decreasing its size removes the size penalty but not the penalty for "dual wielding" you still suffer a -2 for it being the wrong size which is how I ended up at a -4.

Some weapons grant no benefit, the oversized hand crossbow for example does less damage than an appropriately sized light crossbow. Additionally, the oversized hand crossbow must be used two handed and you get a -2 to hit with it. The light crossbow has the same reload speed and you suffer no penalty to hit using it two handed.

An oversized light crossbow is better than a heavy crossbow (more damage and faster reload), but it always takes 2 hands and you have a -4 to hit with it.

The oversized heavy crossbow does slightly more damage than the oversized light crossbow but has a slower reload speed and an additional -2 to hit making it probably not worth it.

The double crossbow is the same as dual wielding, however because it's not actually dual wielding you can't take feats to reduce it's built in penalty. The biggest potential I can see for it is to get two undersized double crossbows and dualwield them. However, even with two-weapon fighting you're looking at a -10 to hit with each, making it likely an ineffective way to fight.

There is of course also the question of reloading. Nothing states that it takes more or less time to reload a weapon that's the wrong size. All of my analysis above assumes that reload times are unaltered. I could easily see a DM stating that it takes longer to reload a weapon that's the wrong size. In which case oversized crossbows may only be practical if you have some way to reduce and/or remove how long it takes you to get your weapon reloaded. Though to be fair, this is something normal crossbow wielders contend with anyway.