D&D 5E SJ Ship to Ship Battles (& Vehicle Rules in General)

[FitzTheRuke]

I ran a Spelljammer session with new players at my LGS on Saturday, and it featured a ship to ship battle (for reference, check out D&D Beyond Spelljammer Academy which AFAIK is free, though you may have had to "claim" it, whatever that means.)

At any rate, there were several things that I had trouble with.

1) Siege weapons. Can you really just (as my players wanted to do), fire a Mangonel at the other ship's Captain? The rules say "targets" and don't specify anything about how that's done. I assume that the Captain can hide below decks, but that doesn't seem very captain-like.
2) The other thing they wanted to do is "target the enemies' weapons" (very Star-Trek-y). Unfortunately, the battle would have raged for several rounds before it would be possible to disable the enemies weapons. HP are designed such that a creature or object is "fine" (fully operational) unless it's at ZERO HP, and then it's destroyed. I made up a "damaged" condition, just so they felt like they were doing something.
3) OTOH, it seemed like it would be possible to fire a Mangonel at the other ship's Mangonel CREW. (See #1 above). At which point, unless they have a backup guy to join the 5-person crew, the Mangonel would then only get to fire every-other round (or so, as it took 5 actions to fire, which could be 5 people using one action each, or one person using 5, or any combo thereof).

I have more to say, but my wife is calling me for dinner. Please comment on that (if you have any understanding of it). I welcome tips on ways you've made it work, if you've run any 5e Vehicle battles at all (I assume that the Decent into Avernus "Road Warrior" cars work similarly. And I know that ships in Saltmarsh do.) Any experiences to share?

 

[Stormonu]

For Magonels, I'd probably have it be an attack at Disadvantage to target a Large object (such as sails, weapons, helm or the like) or random crew. To hit a specific Medium-sized target or smaller, Disadvantage and -2 to -4 to hit. I'd probably disallow such "sniping" at long range since you can't pile Disadvantage on Disadvantage.

For a Ballista, they're a bit more direct fire, and I'd use the normal rules, though trying to hit a Medium-sized or smaller target should probably be -2 to -4 to hit (Long Range sniping then would be Disadvantage and -2/-4).

The Damaged condition sounds like a wonderful use - especialy if you're doing something like weapons fire slower (taking extra or x2 actions), a sail/navigation damage causes move at half rate and the like. Firing at sails (or other manuevering bits), blowing holes into the ship (so you can target what's inside), damaging the Helm, weapons, cargo and other such things sounds like fun addition. Well, until the enemy starts doing it to YOU . You could break the condition into several stages if you really wanted too - Lightly Damaged, Damaged, Heavily Damaged, Destroyed. It would be more bookkeeping, but at the same time neither side has to slog through a bunch of hit points to go from "I'm fine" to "Broken and unusable".

 

[bedir than]

I'm tempted to make siege weapons a tool

 

[Stormonu]

I think there's more comprehensive rules for seige weapons in the DMG, too.

 

[FitzTheRuke]

I think there's more comprehensive rules for seige weapons in the DMG, too.

There aren't, actually. The rules in Spelljammer probably count as slightly more "comprehensive" (unless you are missing Trebuchet, Cannons, and Housed Rams).

 

[FitzTheRuke]

A few other thoughts I've had:

Some systems would have the HP of a mangonel (I'm going to keep using that catapult as an example, both because it works fine as an average, and because it's what my players used) - have the HP include the crew (as in the mangonel works like a monster. Personally, I find that simpler than tracking HP of five (sometimes four) crew members AND the HP of the mangonel itself (which is very high - often a quarter the HP of the entire ship!)

Now, that works fine for NPCs/Monsters, but it doesn't work well when a PC is involved in captaining a mangonel crew.

So... how do we fix this, but keep it simple? (I don't want complex rulesets. I want easy ones that work!) I will think on it and get back to you. Feel free to make suggestions.

 

[dave2008]

I ran a Spelljammer session with new players at my LGS on Saturday, and it featured a ship to ship battle (for reference, check out D&D Beyond Spelljammer Academy which AFAIK is free, though you may have had to "claim" it, whatever that means.)

At any rate, there were several things that I had trouble with.

1) Siege weapons. Can you really just (as my players wanted to do), fire a Mangonel at the other ship's Captain? The rules say "targets" and don't specify anything about how that's done. I assume that the Captain can hide below decks, but that doesn't seem very captain-like.
2) The other thing they wanted to do is "target the enemies' weapons" (very Star-Trek-y). Unfortunately, the battle would have raged for several rounds before it would be possible to disable the enemies weapons. HP are designed such that a creature or object is "fine" (fully operational) unless it's at ZERO HP, and then it's destroyed. I made up a "damaged" condition, just so they felt like they were doing something.
3) OTOH, it seemed like it would be possible to fire a Mangonel at the other ship's Mangonel CREW. (See #1 above). At which point, unless they have a backup guy to join the 5-person crew, the Mangonel would then only get to fire every-other round (or so, as it took 5 actions to fire, which could be 5 people using one action each, or one person using 5, or any combo thereof).

I have more to say, but my wife is calling me for dinner. Please comment on that (if you have any understanding of it). I welcome tips on ways you've made it work, if you've run any 5e Vehicle battles at all (I assume that the Decent into Avernus "Road Warrior" cars work similarly. And I know that ships in Saltmarsh do.) Any experiences to share?

I would allow siege weapons to target people; however, the aren't designed for this purpose so I might make the shot with disadvantage or allow the people a DEX to take half damage (ship or adjacent target might still take damage).

 

[FitzTheRuke]

I would allow siege weapons to target people; however, the aren't designed for this purpose so I might make the shot with disadvantage or allow the people a DEX to take half damage (ship or adjacent target might still take damage).

Yeah, it's tricky. When you want to keep it simple, but (for example), in real-world siege warfare (at least, as I understand it), the chance of getting struck by the ammunition was not very high (and very lethal if you were unlucky), but the chance of being harmed by flying debris (cannons famously burst through ship's hulls sending splinters of oak, which were the real killers of a ship's crew).

But how to emulate that simply, 5e-style?

I've thought of ship-to-ship combat before, and I once had a working ruleset. Unfortunately it was 15+ years ago, and I don't remember it. Plus it was based on a % system, which wouldn't be a good fit. So we're starting from scratch here.

I am thinking of houserules, sure, but I'd like to use as much of what 5e has already done with it as possible, and add as little to it as possible.

Still thinking...

 

[Thommy H-H]

Ghosts of Saltmarsh has more involved ship rules which I think should combine fine with the basic Spelljammer framework. It would be a bit of work though. Much of those rules were also previewed in a UA called "Of Ships and the Sea" from November '18 if you want to take a look without forking out for an adventure you're not planning to use.

 

[FitzTheRuke]

Ghosts of Saltmarsh has more involved ship rules which I think should combine fine with the basic Spelljammer framework. It would be a bit of work though. Much of those rules were also previewed in a UA called "Of Ships and the Sea" from November '18 if you want to take a look without forking out for an adventure you're not planning to use.

I don't think the rules in Ghosts of Saltmarsh nor for the road-warrior vehicles in Decent into Avernus are any more involved. (Looks); Okay, Saltmarsh are a little more involved, giving ships almost-monster stablocks. I'm not sure any of it fixes the trouble I'm having with the system, though.