Will anything break if prone crossbow-wielders get advantage instead of disadvantage?

Question

Being prone imposes disadvantage on attacks, which makes sense for melee weapons and traditional bows. However, for things like crossbows and firearms, laying prone seems like it should have the opposite effect. The additional support and bracing received by laying on the ground would serve to stabilize one's aim, and traditionally sharpshooters in militaries worldwide lay prone when making their long range shots.

Is this an unreasonable idea for balance purposes? Will anything break in my game if I house rule that characters receive advantage from being prone when firing a crossbow, rather than disadvantage?

Answer 1

Historical crossbows are not firearms

Modern crossbows have shoulder stocks like rifles or other long guns, but that is not true of historical crossbows. Because there is no recoil, there is no need for a shoulder stock to disperse it across the body. Modern crossbows have stocks not because they need them but because most users expect them from their exposure to rifles.

Historical crossbows can be more accurately described as having a stick:

They were fired by holding them up to your eye and sighting along the shaft, a posture that would break your cheekbone with a firearm.

Rifles and modern crossbows can be fired comfortably from a prone position because the shoulder stock allows for it. Historical crossbows are virtually impossible to aim from a prone position, and the disadvantage is warranted.

Nothing will break

Largely because "balance" in D&D 5e is a very big target. In certain situations, it will make a fight slightly easier for the crossbow wieldier's side and slightly harder for the other side, but not to the extent that it will "break" anything.

A crossbow wielder who tries to spend combat prone is sacrificing much of their mobility, and intelligent foes should take advantage of that. A Fog Cloud or Darkness spell will negate the advantage. Spells that require saving throws aren't affected when targeting a prone creature, and getting up close is always a go-to move against any missile user.

If the crossbow user is a PC, this will make things a bit easier - who cares, PCs are meant to win anyway. If they are on team monster, this will make the fights harders - it will take longer to down the monster crossbow users and they will get more hits on the PCs, you will need to factor that in. Notwithstanding, its far less of an advantage than if the crossbow users were behind arrowslits.

Answer 2

This is an unbalanced option and will likely result in a crossbow wielder dropping prone every or nearly every round.

Per the being prone rules (PHB 190):

You can drop prone without using any of your speed. Standing up takes more effort; doing so costs an amount of movement equal to half your speed.

This means that ranged attackers can drop prone before making their attacks for the round with advantage, and then rise for half of their movement to avoid any penalties from being prone before they end their turn. This allows ranged attackers to trade the resource they value least (movement) for advantage on any attack.

When considering balance, it is best to look at a feature or option that gives an equivalent benefit. The most obvious mirror (and the character I would expect to take advantage of this rule the most) is the Rogue's Cunning Action to Hide.

Like your Prone rule, the Rogue can consistently get advantage on their attacks by hiding every round they can find cover. In Cunning Action, this is offset by requiring a bonus action and a stealth check, which may fail. Your Prone rule, on the other hand, works on any round that the rogue does not require more than half of their available movement.

Answer 3

This is unnecessary

Before discussing any balance impact, let's talk about what are we trying to fix.

for things like crossbows and firearms, laying prone seems like it should have the opposite effect

So there are no gameplay nor tactics issues. The only problem is: imposing disadvantage might seem unjustified for someone.

If this "someone" is you, I suggest you reconsider. Within the 5e rules, crossbows work just like any other ranged weapon. This is intended, since 5e approach is to simplify the rules. Don't add more rules without a substantional reason. Players won't appreciate that.

If it's a player who is complaining, you don't actually need to rebalance crossbows in order to solve the issue. You need a plausible explanation, why disadvantage is still applied. Such an explanation might be:

• Hard to reload. You have to reload the crossbow in the same turn, but it's hard to do that while being prone. You shoot in a rush, hence the disadvantage.
• No proper support. You can't firmly place the crossbow on the ground, so you have to hold it suspended in midair.
• Uncomfortable position. Wet mud. Et cetera.

"Prone" condition often implies unconvinient circumstances, so the player should agree.

If the situation is ideal for shooting in prone position, you the DM can make an exception and grant an advantage in this particular case. What you shouldn't do — prematurely turn this ruling into a rule.

This is also unbalanced

But not in terms of unfair advantage. Range attackers try to stay in the backline anyway. Being prone becomes no-brainer in this case. It's just a "give me advantage" button, which they can freely spam. This spends your group's real time and reduces weapon diversity (crossbows become superior). This is not fun.

The closest alternative to this is the optional Flanking rule:

flanking gives combatants a simple way to gain advantage on attack rolls against a common enemy.

So it's also a free advantage, although, it still works only in melee:

they flank that enemy, and each of them has advantage on melee attack rolls against that enemy.

This seems intentional. Flanking rule adds tactical options — you have to actively reposition youself, not just say "I'm flanking". However, from my experience, it still feels very "spamy", when players are trying to flank on each turn. So I personally don't use this rule, albeit I use the grid most of the time.

Answer 4

This is very risky

First, it's not that easy to break the game with a rule change. Even in the existing rules there is a good amount of power variance, and that may be a good thing too, as it gives players something to explore and discover as they become more expert in the system.

For a change to really break something, it typically needs for that feature to be so powerful that it overshadows other approaches, and leads to repetitive play patterns, or so weak nobody is using it, and the class that gets the change becoming unattractive to play. You also need to look at how it can be abused in a focused build, because even if it is fine in others, that is how someone will use it.

Reasons this might be fine:

First, the change is somewhat symmetrical. It will benefit monsters with crossbows, as much as players. Players of course can use it all the time, and most monsters do not have them (at least, as given in the MM), so it will benefit players more, but at least it's possible to be used against them.

Second, it's open to many. Light crossbows are simple weapons that pretty much everyone can use, so it will not enhance just one class and make it better. It still of course favors a build that wants to use a ranged weapon more.

Third, there are other ways to get advantage on attacks, although many of them are harder to engineer than simply dropping prone: you can attack from being invisible or in darkness with devil sight or by being a gloom stalker ranger, or have your familiar or some minion use the help action.

Forth, and most importantly using it has a cost: when you drop prone, you sacrifice mobility. It will be harder to get away if someone gets close, and anyone who manages to get within 5 feet also has advantage to hit you.

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Still, I think this is risky: advantage is a big swing approximately worth +4 or +5 to hit, and your optimized crossbow expert and sharpshooter fighter always attacking with advantage to add +10 to damage at no real cost can be quite overpowered. With crossbow expert, they even get an added bonus action attack to make it worse. It will be easier and even more problematic than other ways to do exploit sharpshooter with advantage, and a build exploiting sharpshooter with advantage nearly broke our game.

Your motivation is verisimilitude. By that measure, if you think about how crossbows were cocked in the real world, with belt hooks and such, it may be easier to aim, but it also might be harder to reload the crossbow.

I would at least exclude hand crossbows from this, and state that you cannot avoid the loading cost if you do this, so crossbow expert builds will not exploit this to unbalance your game.

Answer 5

Your proposal is to change two things at once which need to be addressed separately.

Avoiding this Disadvantage is Balanced.

The general rule on disadvantage when prone is reasonably there due to how most weapons in the rules require a lot of force and movement be applied at the time of attack. But crossbows are so different from almost all other weapons due to how they only need to release the string to attack, not apply force to the attack at the moment of attack.

It also doesn't matter much as there is already a way to avoid this disadvantage which is simply to stand up on your turn to shoot then drop prone again. The effect is that your movement is effectively only halved since standing up consumed half your movement.

So it both helps with keeping players immersed as things are intuitive and doesn't significantly change the existing capabilities of players.

Advantage at such low cost is Not Balanced.

This would be a way to get advantage at essentially only a slight cost in movement, it would not require any consideration to the environment, no class ability nor feat, no skill check. Even class abilities such as Reckless Attack guarantee advantage on being attacked when in melee which is very different from guaranteeing advantage when far out of melee range.

This is just unprecedented in D&D 5th edition. This would make crossbows by far and away far too enticing.

A houserule may be unnecessary just to avoid Disadvantage

My favorite obscure rule 5th Edition is the DM Advantage Fiat on Page 173 of the PHB.

The DM can also decide that circumstances influence a roll in one direction or the other and grant advantage or impose disadvantage as a result.

This is such a vital rule and the DM may just agree that in most circumstances the advantages of steadying a crossbow on the ground counteracts the disadvantage of not using your legs for balance. This has the added effect of preventing the attack ever being with advantage as no matter how many more sources of advantage you get you remain with a normal roll.

I know this may not be as certain but it may be necessary to trust the DM with this to prevent absurd situations like laying down prone facing down a flight of stairs to shoot at an opponent above you. Even if you rolled onto your back you wouldn't be bracing your crossbow against the ground, you'd just have all the instability of laying on your back rather than standing on your feet.

Real Life Lore

Shooting when prone is not all that easy, while it is advantageous to be able to brace your arms against the ground it is at the cost of not being able to plant your feet firmly on the ground to control the weapon. Historically, the most advantageous shooting position was where you're standing upright but your projectile weapon is braced on a solid surface such as the edge of a trench. So it is consistent that shooting while prone is advantage and disadvantage competing with each other.

Rifle shooting is often prone because:

• it's safer, the rifle can't be dropped far and people tend to not turn around quickly pointing a gun in a careless direction.
• it's following old military traditions which require prone shooting
• it's easier if you have lots of equipment to lay it all on the ground, also, can't be dropped far and damaged
• There are ballistic advantages to being slightly lower than your target as shots will have a plateau near the apex.

Answer 6

Try imposing a disadvantage to this maneuver to keep it balanced

Why not make it similar to the 'steady aim' feature that rogues get from Tasha's? I would say, they can go prone on their turn and steady their aim, or they must start their turn prone, and they must stay prone until their next turn otherwise they'll be able to abuse it as you mentioned. That way, if someone gets to their position they are left vulnerable as a sharpshooter would in that circumstance. In addition, it shouldn't step on the Rogue's toes because the rogue does not need to be prone.