Big Mac wrote: ↑Wed Jun 22, 2016 10:11 pm

How do the combat rules compare to Spelljammer ship combat? Can I take Birthright ships and use them in Spelljammer (and vice-vera)?

So, four years later, here's a rough guesstimate for each ship mentioned in

*Cities of the Sun* and

*Dragon* #232:

Dromond (Khinasi) - 20,000 gp

Tonnage: 4 tons (SJ), 10 tons (HJ)

MC: C

AR: 9

1 Weapon

60'x16.4'x10'

Greatship (Anuirean, Rjurik) - 40,000 gp

Tonnage: 57 tons (SJ), 153 tons (HJ)

MC: E

AR: 8

2 Weapons

140'x36.5'x30'

Galleass (Anuirean, Khinasi) - 28,000 gp

Tonnage: 19 tons (SJ), 50 tons (HJ)

MC: E

AR: 8

4 Weapons

100'x25'x20'

Caravel (Anuirean) - 12,000 gp

Tonnage: 4 tons (SJ), 11 tons (HJ)

MC: D

AR: 8

1 Weapon

60'x18'x10'

Coaster (Anuirean, Brecht) - 4,000 gp

Tonnage: 1 ton (SJ), 1 ton (HJ)

MC: C

AR: 10

No weapons

20'x5.7'x10'

Cog (Rjurik, Brecht) - 10,000 gp

Tonnage: 4 tons (SJ), 11 tons (HJ)

MC: E

AR: 8

2 Weapons

60'x18.9'x10'

Dhoura (Khinasi) - 8,000 gp

Tonnage: 4 tons (SJ), 11 tons (HJ)

MC: D

AR: 8

1 Weapon

60'x18'x10'

Dhow (Khinasi) - 4,000 gp

Tonnage: 1 ton (SJ), 1 tons (HJ)

MC: C

AR: 10

No weapons

20'x5.5'x10'

Drakkar (Vos) - 16,000 gp

Tonnage: 3 tons (SJ), 9 tons (HJ)

MC: F

AR: 8

No weapons

60'x15.7'x10'

Galleon (Anuirean) - 30,000 gp

Tonnage: 62 tons (SJ), 168 tons (HJ)

MC: D

AR: 7

2 Weapons

140'x40'x30'

Knarr (Rjurik) - 12,000 gp

Tonnage: 4 tons (SJ), 11 tons (HJ)

MC: E

AR: 8

1 Weapon

60'x18'x10'

Longship (Vos, Rjurik) - 6,000 gp

Tonnage: 1 ton (SJ), 1 ton (HJ)

MC: E

AR: 8

No weapons

20'x5.5'x10'

Roundship (Brecht) - 24,000 gp

Tonnage: 25 tons (SJ), 67 tons (HJ)

MC: D

AR: 7

4 Weapons

100'x33.3'x20'

Zebec (Khinasi) - 34,000 gp

Tonnage: 21 tons (SJ), 57 tons (HJ)

MC: C

AR: 9

3 Weapons

100'x28.6'x20'

My methodology: Of Ships and the Sea, combined with Dragon #250, gives a total of 5 ship sizes: Small (19 feet or less), Medium (20-59 feet), Large (60-100 feet), Very Large (101-139 feet), and Huge (140+ feet). Naval War Cards have 1 to 4 hits. Vessels with one hit were assigned the minmum Medium length, 2 the minimum Large length, etc. This gives us a minimum for each ship; they can be played around with to generate larger ships of the same class*.

Each ship also has a Seaworthiness stat. OS&S notes that this is loosely based on beam. The stat varies from 12 to 18. I divided that stat by 6 (to get a number between 2 and 3) and subtracted that number from 6 to get a number between 3 and 4. I then divided the length by that number to get a beam. It's a bit complicated to explain, but basically the higher the Seaworthiness, the wider the ship.

For height, I used the Hull Size minus 1 to and gave the ship that many 10' high decks, with a minimum of 1.

Multiplying these together gave the total cubic footage, which was multiplied by .037037 to calculate cubic yards and divided by 100 for SJ tonnage, or just divided by 1000 for HJ tonnage.

Prices are straight from the sources, at the conversion rate of 1 GB = 2,000 gp. Some ships are overly expensive, generally because of a lack of seafaring tradition (Rjurik and Vos) or because a ship is built only for war and is thus rarer than the dual-purpose war/trade ships (Zebec).

MC is the ship's Birthright MC, minus 2 classes for being a groundling vessel.

AR is 11 minus the ship's Defense, so Defense 1 is AR 10, etc.

The number of Weapons is the ship's Missile rating. Most of them would enter space with a larger number of weak artillery primarily intended for anti-personnel use (see below) and would need to be retrofitted with better weapons after entering Wildspace.

I don't have crew estimates or cargo capacity, but most should have large crews. The cargo measure for ships in Birthright is based on value, not weight. Ships with an AR of 9 or 10 save as Thin Wood, the remainder as Thick Wood.

The arbalest does 3d3 (character scale) damage, shot ballista does 1d8 damage, the mangonel 1d8+1, and the catapult 2d6 - the last of those is equivalent to a light ballista, so none of these should do hull damage against Spelljammer vessels. However, all of the weapons except the arbalest can fire incendiary shot. For each point of damage dealt by an incendiary shot, there is a 5% chance of the target ship needing to make a saving throw vs. fire or suffer a Fire critical hit (i.e. a shot ballista firing incendiary shot and hitting has a 5-40% chance of forcing its target to make a save vs. Fire). Naturally, incendiary shot cannot be used in the phlogiston.

Coasters, dhow, and longships can mount 4 arbalests, 2 shot ballista, and 1 mangonel. Dromonds, caravels, cogs, dhouras, drakkars, and knarrs can mount 8 arbalests, 4 shot ballista, 2 mangonels, and 1 catapult. Zebecs and galleasses can mount 12 arbalests, 6 shot ballista, 3 mangonels, and 1 catapult. Greatships and galleons can mount 16 arbalests, 8 shot ballista, 4 mangonels, and 1 catapult. Roundships can mount 12 arbalests, 6 shot ballista, 3 mangonels, and 2 catapults. Most of the smaller ships will mount fewer weapons, since they are trading ships and weapons cost money. Larger ships are more likely to be war ships and mount most or all of their possible weapons.

Rare ships might be armed with hellpowder weapons, which Brecht and Khinasi alchemists have been experimenting with for the past generation; the dragon is an anti-personnel weapon that does 1d12 damage and replaces arbalests on a 1 for 1 basis, while bombards are large-bore, short-barreled cannon firing stones weighing 60-90 pounds and dealing 2d10 damage (equivalent to a SJ light catapult, so 1d2 hull damage); they replace mangonels (while not in the rules as written, I would also allow them to replace catapults). Petards are explosive ammunition that can be flung from a mangonel or catapult to inflict damage as a medium ballista (3d6 hit points/1d3 hull points). None of the hellpowder weapons can be used in the phlogiston.

Ranges are in tens of yards, so all of the weapons are same-hex only except for the catapult, which has a range of 1 hex in Spelljammer. Given the lack of a surface for shots to hit, I would argue for a skilled gunner (average or better crew quality per the

*Concordance of Arcane Space*) being able to double these ranges, at which point the catapult would have a 2 hex range and everything else except the shot ballista a 1 hex range.

Arbalest - crew 3, range 10/20/40, THAC0 per shooter, ROF 1/3, 350 gp

Shot ballista - crew 4, range 5/10/15, THAC0 12, ROF 1/4, 800 gp

Mangonel - crew 3, range 8/16/24, THAC0 14, ROF 1/5, 1000 gp

Catapult - crew 6, range -/20/50, THAC0 16, ROF 1/6, 2000 gp

Dragon - crew 3, range 8/16/24, THAC0 13, ROF 1/3, cost not listed

Bombard - crew 8, range 5/20/40, THAC0 15, ROF 1/5, 10000 gp

*For example, a maximum size Roundship is 139'x46.3'x20', and is 48 SJ tons or 129 HJ tons instead of the 25/67 of the minimum size. The 20' 1/1 ships become 2/5 if doubled in length to 40'. A king's prestige galleon might be 200'x57.1'x30' and be unable to fly in Spelljammer at 127 tons, but mass in at 343 tons in Hackjammer.