Naval Combat retry

[Kane0]

So long ago when the Naval Combat UA was released I took a copy and made some adjustments. Then promptly put it in my 'under development' folder and forgot about it.
But now I'm DMing a game that is most likely going to involve pirates and island hopping, so I pulled it out from the backburner and started tinkering again in anticipation for the inevitable day the party decides to take on another vessel.
Of course since then Saltmarsh has been published with few if any changes to the UA, so at this point what I have is pretty divergent.

Anyways, here is my current draft! I've run a quick playtest but hoping to get some more opinions before the party gets keelhauled.
Please note this assumes you are using a hex grid and in this case one hex = 25 feet instead of the usual 5 to portray the greater distances involved.

The basics:
Your vessel has a few stats: Size, Hull, Propulsion, Crew, Handling and Weaponry. Cargo capacity is not directly factored in but may become important.
Size: Determines the number of dice you roll for Hull/Propulsion/Crew (see below), how well your ship handles (its ability to turn) and its cargo/weapons capacity
Hull: determines vessel AC, Hull HP and Threshold
Propulsion: determines top speed, Propulsion HP and Threshold
Crew: determines bonuses to attacks/checks/saves, Crew HP and Threshold
Handling: How many hexes forward you have to move before you can turn one hex face. Eg 'Handling 1 per 2' means 'Can turn one hex face for every two hexes moved', ie you need to move forward 2 spaces in order to turn one face left or right



Ship Size
Hull
Propulsion
Crew
Handling
Weapons


Tiny
3dx
2dx
1dx
1 per 0
1


Small
6dx
4dx
2dx
1 per 1
2


Medium
10dx
8dx
6dx
1 per 2
4


Large
12dx
10dx
8dx
1 per 2
6


Huge
16dx
14dx
12dx
1 per 3
8


Immense
20dx
18dx
16dx
1 per 4
10



The quality of hull, Propulsion and crew determines their die size and damage threshold. Threshold is taken straight from the UA, if damage taken falls below the threshold it is ignored.

Taking turns
- First you roll initiative for each vessel, as usual in D&D. Use the captains Initiative bonus if the captain is a PC, otherwise use the ship's Crew Bonus (attack/ability bonus, not save bonus).
- When your vessel takes its turn it can perform its movement (see speed and handling), which may be impacted by weather and other conditions, and can take one action at any point during movement

Attack Action: Fire any available weapons the vessel has (and has ammo for), using the attack bonus of the PC manning it or otherwise the Crew attack/ability bonus

Board Action: Attempt one opposed check against another vessel adjacent to your vessel. PCs leading the boarding attempt can make the check otherwise use the Crew attack/ability bonus. Three successes before three failures are required to successfully board and pacify an enemy vessel

Evade Action: Your vessel gains an additional 2 movement and enemy attacks (not boarding attempts) are made at disadvantage until the start of your next turn
- During a vessel's turn, if a PC aboard the vessel has not taken part in any of the above actions they can take one action or bonus action, such as casting a spell

Taking Damage
Ship weaponry deal Hull (H), Propulsion (R) or Crew (C) damage instead of Bludgeoning/Piercing/Slashing, which ignores the Threshold rules. B/P/S damage is subject to Threshold values.
- A vessel reduced to 0 Hull HP begins to sink, which usually takes about 1d6 rounds
- A vessel reduced to 0 Propulsion HP is immobilized and cannot move nor take the Evade action. It can still fire weapons and attempt to board/fend off boarding attempts if another vessel nears it
- A vessel reduced to 0 Crew HP has been reduced to insufficient manpower and morale and suffers disadvantage on all rolls, half movement speed and must start making death saving throws to continue taking actions or fend off boarding attempts



Sample Weapons
Range
Damage


Ram
0
{Movement}d8 (H)


Ballista
6/18
1d6 (R or C)


Catapult
8/24 (min 3)
1d8 (see ammo)


Cannon
10/30
1d8 (H or R)


Bow/Crossbow
1 = 25'
1d2 (R or C)


Spell
1 = 25'
Ask your DM



Ammunition types:
Solid: Hull or Propulsion damage
Cluster: Propulsion or Crew damage
Toxic: Crew damage
Alchemists Fire: Hull, Propulsion or Crew damage
Alchemists Frost: Hull or Crew damage
Smoke: No damage, instead obscures surrounding area
Powder bomb: Propulsion or Crew damage
Defoliant: Hull damage



Hull Quality
Die Size
Armor Class
Threshold


Rotten
d4s
AC 12
5 Damage


Standard
d6s
AC 14
10 Damage


Reinforced
d8s
AC 16
15 Damage


Alchemical
d10s
AC 16
20 Damage


Magical
d12s
AC 18
25 Damage





Propulsion Quality
Die Size
Move Speed
Threshold


Rotten
d4s
3
4 Damage


Standard
d6s
4
8 Damage


Reinforced
d8s
5
12 Damage


Alchemical
d10s
5
16 Damage


Magical
d12s
6
20 Damage





Crew Quality
Die Size
Attacks, Checks & Saves
Threshold


Skeleton
d4s
+2 / +2
3 Damage


Rough
d6s
+4 / +3
6 Damage


Standard
d8s
+6 / +4
9 Damage


Veteran
d10s
+8 / +5
12 Damage


Elite
d12s
+10 / +6
15 Damage



Sample Statblock: Trading Carrack
Size Medium (Standard Hull, Propulsion & Crew)
Movement: 4 (turn 1 per 2)
AC 14
Hull HP: 45 (10d8), Threshold 10
Propulsion HP: 28 (8d6), Threshold 8
Crew HP: 27 (6d8), Threshold 9
Crew Attack/Check: +6
Crew Saving Throw: +4
Weapons: 2x Ballista (Range 6/18, 1d6 R/C damage)
Cargo Capacity: 100 Tons

[SandyAndy]

When I do naval combat (including airships and spaceships) I keep in mind that there are a lot of things going on. It's not one ship against another ship, its a crew against another crew; so it doesn't work as much like stat blocks in normal combat.

What I do is divide it into bridge crew, deckhands, gunnery, and damage control. The bridge would be determining the speed and direction of the vessel. The deckhands would be working the rigging, boarding/repelling boarders, and moving supplies as needed. The gunnery crew would need to acquire firing solutions, load and fire the armament, and manage dangerous munitions. Damage control would be doing impromptu repairs and handling the wounded.

Each player winds up working a team in one of those sections and we wind up jumping between them during the fight. That way you get the personal feeling of combat but maintain that nautical setting. *Master and Commander*, *Star Trek*, and *The Expanse* are good references for that kind of story telling.

That being said, I like your stat block generation system. It's a good mechanical support for the story aspect.

[Kane0]

Yeah differentiating the ways you can attack and be attacked is something I wanted to hold onto without going down the path of individual stats for locations and items on the ship (like how the Saltmarsh rules do it). Something that allows for different methods of dealing with enemy ships without bogging down gameplay.

Converting to spaceships wouldn't need much effort, largely a case of putting in some new weapons and changing 'rigging' to 'propulsion'
Actually it would probably make sense to do that by default, considering oars vs sails.

Edit: When it comes to onboard PC interaction I'd like to think they would split up and work on emergency repairs, using weapons, patching up crew, manipulating the battlefield and steering the ship but that will need further playtesting to see if that actually happens. I certainly didn't want to tie the ship down so it can only function with character input, I did want them to be largely self-contained but benefit from PCs/named NPCs pitching in.