[HR] Naval Rules

This is a very rough draft. If there’s any clarification necessary or suggestions, please feel free to offer ideas. Sources used for this document include:
Adventurer, Conqueror, King
“Actium: End of the Roman Republic” (Strategy & Tactics #281, Jul-Aug 2013)

Technical notes: HackJammer was used only to derive a formula for the cost of ships, since I couldn’t get ACKS’ galley costs to work nicely for me. The SHP of the small and large galley were used to derive a formula for calculating SHP for larger vessels. The Actium article was used for information on crew size and artillery loadout. The rule for replacing artillery with marines is based on the (large) discrepancies in sources for amount of artillery and number of soldiers carried at various times aboard these types of ships. The number of turns is based on maneuverability ratings from “Actium” and technical reports on the trireme Olympias that reported it could make a 180 degree turn in 1 minute.

Naval combat:

Use a hex map. Each hex is considered to be 30 feet (10 yards) across.

Sustained rowing: Sustained rowing is a steady stroke from the oarsmen that can be sustained for hours if needed. It is just quick enough to ram an enemy if they get close, but since most oared ships have similar sustained speeds, it is difficult to close with an unwilling enemy using sustained rowing.

Burst rowing: Burst rowing is an all-out effort from the oarsmen, and is tiring. A ship can automatically burst row for 2d3 rounds; each round after that, it must make a morale check, with each check after the first at a cumulative -1 penalty. Note that most rowers are considered conscripts (-2 morale). On a result of hostility or resignation, the rowers can no longer maintain burst rowing. The ship immediately drops to Sustained speed and takes a -1 speed penalty for 2d6 rounds. After this time is up, the Sustained speed returns to normal and the ship can Burst speed again.

Example: A octeres wants to close with a trireme. Its captain has a 14 charisma, granting +1 to morale rolls, and the crew are conscripts, inflicting a -2 penalty to morale rolls. The captain rolls 2d3, and the ship can Burst row for 5 rounds. The sixth round, the crew makes a morale check at -1 (+1 for CHA, -2 for conscripts). The captain rolls an 8, modified to 7, and the ship can continue at Burst speed. The seventh round, the crew makes a morale check at -2 (+1 for CHA, -2 conscripts, -1 cumulative penalty). The captain rolls a 3, modified to 1, and the ship immediately drops to its Sustained speed with a -1 hex speed penalty. The captain rolls 2d6, and finds his ship will be slowed for 10 rounds while the rowers recover.

Turns: Each ship has a fractional turn rating. The bireme may make one turn per round. Triremes can only turn every other round, while the largest warships can only make one turn every 6 rounds. Note that ships do not have to move in order to turn, but stationary ships do not normally turn any faster than moving ships. A stationary ship can choose to back one bank of oars. If it does so, it requires one round stationary to prepare. It may then turn at one hexside per round for any number of rounds, then requires one round to prepare to move forward again.

Light Hulls, Standard Hulls, and Armored Hulls: The ship stats presented below are for Standard Hulls. Ships may be built with lighter planking for improved speed or can be sheathed with bronze armor for more protection. A light-hulled ship reduces its AC from 5 to 3, but gains +1 to morale checks for Burst rowing. An armored ship improves its AC from 5 to 6, but has a -1 penalty to morale checks for Burst rowing.

Artillery: Most vessels carry artillery on board. The age of ramming declined when massed fleets became more common, and the large polyremes are less suited for a battle of maneuver than the old biremes. Each ship is presented with the maximum number of artillery weapons that can be placed on its deck. Artillery can be removed for additional sailors or marines. Heavy combat ships use towers to improve the field of fire of their artillery. Ships with towers may carry two ballistas in the towers. Each ballista can fire into either broadside. One can fire to the fore, the other to the aft. All heavy combat ships can carry two weapons (of any type) firing to the fire and two (of any type) firing after. Half of all their non-tower weapons can fire into each broadside.
Biremes and Triremes are Light combat ships, and do not have towers. Biremes can mount one weapon firing forward and one firing aft, with each able to fire into either broadside. Triremes mount two weapons firing one direction and one firing the other (either two fore and one aft or one fore and two aft); the lone weapon can fire into either broadside, while the paired weapons can each fire into one broadside.

Firing arcs: The broadside covers all hexes except those directly in front of or behind the ship. Ships either directly in front of or behind another ship can only be fired on by their fore or aft weapons respectively. Thus, a fore tower ballista can fire into any hex within range except the line of hexes directly behind the ship, while an aft port onager can fire directly behind the ship or into any hex to the left of the ship in an arc that extends to (but does not include) the line of hexes directly in front of the ship.

Marines: Marines are used in close combat or boarding combat. They can be hired per the mercenary table in the ACKs core rulebook. For each artillery weapon removed from a ship, 10 additional marines may be carried. Since the type of marine carried will vary, cost of marines is not included in the crew cost of a ship. Marines are assumed to be responsible for the firing of artillery; if no marines are carried, sailors can fire the artillery, but at a -1 attack penalty.

Monthly crew cost: The monthly crew costs in this document include the cost for a captain and a navigator, and utilize the Mariner costs from page 54 of ACKs. Costs exclude the cost of marines, as their equipment (and thus cost) will vary.

Missile weapon ranges in hexes:
Arbalest – short range 3, medium range 6, long range 12
Bow, Composite or Bow, Long – short range 2, medium range 4, long range 7
Bow, Short – short range 1, medium range 3, long range 5
Crossbow – short range 2, medium range 5, long range 8
Dart – short range 0, medium range 1, long range 2
Javelin – short range 0, medium range 1, long range 2
Sling – short range 1, medium range 3, long range 6
Ballista – short range 5, medium range 10, long range 20
Onager – minimum range 5, short range 10, medium range 20, long range 40
Only the ballista and onager do shp damage. They may be aimed at a ship in general or at a specific target on board the ship. All other weapons must be aimed at a specific target. The onager cannot fire at targets closer than 5 hexes, due to the arc of its projectile.

Crew on deck are considered exposed and may be fired at using their standard AC. Rowers on bottom levels are considered behind a barrier and cannot be shot (although they may be accidentally struck by ballista or onager shots). Top level rowers are considered covered and are attacked as if they were AC 4.

Rate of Fire, Attacks As and Damage are as per ACKs. Range is per the missile weapons information in this file.

Rate of Fire, Attacks As and Damage are as per ACKs. Range is per the missile weapons information in this file.

Ship information:
Bireme (Light Warship)
SHP: 100
AC: 5
Sustained speed: 3
Burst speed: 6
Turns: 1/1
Onagers: 1
Ballistae: 1
Rowers: 144
Sailors: 10
Marines: 15
Light ship cost: 9,750 gp
Standard ship cost: 13,000 gp
Armored ship cost: 32,500 gp
Artillery cost: 280 gp
Monthly crew cost: 605 gp

Trireme (Light Warship)
SHP: 120
AC: 5
Sustained speed: 3
Burst speed: 5
Turns: 1/2
Onagers: 2
Ballistae: 1
Rowers: 180
Sailors: 15
Marines: 20
Light ship cost: 12,000 gp
Standard ship cost: 16,000 gp
Armored ship cost: 40,000 gp
Artillery cost: 480 gp
Monthly crew cost: 743 gp

Quadrireme (Heavy Warship)
SHP: 175
AC: 5
Sustained speed: 3
Burst speed: 5
Turns: 1/2
Onagers: 3
Ballistae: 2
Rowers: 220
Sailors: 30
Marines: 30
Light ship cost: 18,000 gp
Standard ship cost: 24,000 gp
Armored ship cost: 60,000 gp
Artillery cost: 760 gp
Monthly crew cost: 953 gp

Quinquereme (Heavy Warship)
SHP: 215
AC: 5
Sustained speed: 3
Burst speed: 5
Turns: 1/2
Onagers: 4
Ballistae: 3
Rowers: 270
Sailors: 30
Marines: 40
Light ship cost: 22,500 gp
Standard ship cost: 30,000 gp
Armored ship cost: 75,000 gp
Artillery cost: 1,040 gp
Monthly crew cost: 1,103 gp

Hexareme (Heavy Warship)
SHP: 250
AC: 5
Sustained speed: 3
Burst speed: 5
Turns: 1/3
Onagers: 5
Ballistae: 4
Rowers: 330
Sailors: 30
Marines: 50
Light ship cost: 27,000 gp
Standard ship cost: 36,000 gp
Armored ship cost: 90,000 gp
Artillery cost: 1,320 gp
Monthly crew cost: 1,283 gp

Septireme (Heavy Warship)
SHP: 285
AC: 5
Sustained speed: 3
Burst speed: 5
Turns: 1/3
Onagers: 6
Ballistae: 5
Rowers: 385
Sailors: 30
Marines: 60
Light ship cost: 31,500 gp
Standard ship cost: 42,000 gp
Armored ship cost: 105,000 gp
Artillery cost: 1,600 gp
Monthly crew cost: 1,448 gp

Octeres (Heavy Warship)
SHP: 315
AC: 5
Sustained speed: 3
Burst speed: 5
Turns: 1/6
Onagers: 8
Ballistae: 6
Rowers: 440
Sailors: 30
Marines: 70
Light ship cost: 36,000 gp
Standard ship cost: 48,000 gp
Armored ship cost: 120,000 gp
Artillery cost: 2,080 gp
Monthly crew cost: 1,613 gp

Enneres (Heavy Warship)
SHP: 345
AC: 5
Sustained speed: 3
Burst speed: 5
Turns: 1/6
Onagers: 10
Ballistae: 8
Rowers: 504
Sailors: 30
Marines: 80
Light ship cost: 40,500 gp
Standard ship cost: 54,000 gp
Armored ship cost: 135,000 gp
Artillery cost: 2,640 gp
Monthly crew cost: 1,805 gp

Deceres (Heavy Warship)
SHP: 370
AC: 5
Sustained speed: 3
Burst speed: 5
Turns: 1/6
Onagers: 12
Ballistae: 10
Rowers: 570
Sailors: 30
Marines: 90
Light ship cost: 45,000 gp
Standard ship cost: 60,000 gp
Armored ship cost: 150,000 gp
Artillery cost: 3,200 gp
Monthly crew cost: 2,003 gp

Two tweaks I’m currently working on:

  1. A Critical Hit table to allow for weapons to be damaged/destroyed, ship speed to be damaged, rudders to be jammed/destroyed, etc.

  2. Narrowing firing arcs a bit. After a little testing, the lack of maneuverability of the super-heavy polyremes isn’t as much of a liability as it should be because of the wide arcs. There will end up being 10 arcs a weapon can be placed into - Forward, Forward Port, Forward Starboard, Port Broadside, Starboard Broadside, Aft, Aft Port, Aft Starboard, Fore Tower, and Aft Tower.

Neat! I really like the usage of the Reaction table for the rowing.

Random thoughts:

Are any of the ships larger than a hex?

Is there a use in knowing rowers per row/side, in the case of needing to have them affected by damage (crit hit, etc.?)

All those parts and locations gets me imagining a Battletech-style sheet for the ships :slight_smile:

“Are any of the ships larger than a hex?”

Yes, all of them are (and that’s something I didn’t think of before). Which is going to require some thought on how multi-hex ships will interact with firing arcs and how turning will operate (current thought is that a weapon can fire on a ship if any of its hexes are in the weapon’s arc, and that ships will turn around the front inside corner, so a left turn will mean the front left hex is the pivot, mirrored for a right turn).
Biremes through quadriremes will be 3 hexes long and 2 hexes wide (due to oars - they range from 108 feet by 16 feet with 16-foot-long oars to 115 feet by 16 feet with 20-foot-long oars). It looks like fives, sixes, and sevens will be 4 x 2, while eights and nines will be 4 x 3 and tens will be 5 x 3.

One positive side effect is that it’ll be possible to position marines on the decks of ships for boarding actions so that (for example) missile troops can stay on the starboard side if they’re being boarded from the port side.

“Is there a use in knowing rowers per row/side, in the case of needing to have them affected by damage (crit hit, etc.?)”

I’m not totally sure yet, but probably. To avoid the argument on whether polyremes were rowed as biremes or triremes, I’m expecting the crit for rower casualties to be something along the lines of “inflict normal damage and kill 1d6 columns of rowers,” while small missile weapons can attempt to pick off individual rowers (or marines, or the captain if they’re unsporting types and can get a clear shot at him). For a bireme, loss of 1d6 columns would mean losing 2 to 12 rowers (because each column is 2 rowers), while for a deceres it would be 10 to 60 (because each column is 10 rowers). I don’t want to get down to it mattering exactly where they’re lost, because tracking that for each ship would slow play down quite a lot if there are multiple ships on each side. It’s much quicker to just note that you’ve lost X rowers and have Y rowers remaining.

I’ll need some playtesting on it, but currently I’m thinking loss of 1 point of Sustained speed and 2 points of Burst speed will happen at 1/4 and 1/2 rowers lost, so most ships will drop to 2/3 when they’ve lost 1/4 of their rowers and 1 when they’ve lost 1/2 (with the bireme dropping to 2/4 and 1/2). Other crits will involve throwing off the rowers rhythm (loss of speed for a short time), breaking oars (hope you brought spares), destroying weapons, inflicting splinter damage to the navigator, captain, or marines, or rudder damage (can only turn in one direction or needs one more round to make any turn).

“All those parts and locations gets me imagining a Battletech-style sheet for the ships :)”
I want to keep it a little more abstract than that. My inspiration for this was actually Spelljammer, since that treated space combat like naval combat and (mostly) worked. While I like BattleTech, it tends to slow down horribly when large battles occur. By keeping it more abstract and referencing fewer charts during combat, it keeps things a little quicker. It probably will be useful to have some sort of ship sheet, but it’ll be mostly to record the shp, number of crew, and the weapon arcs.

You know, I’ve never even seen Spelljammer. I should see about rectifying that.

Are the 8s+ the only ones wider than a hex discounting oar length? Would it be worth “assuming” the oar space to get more ships 1 hex wide, under the rationale that space gets taken up by alongside actions? (keeping in mind the ability to get up alongside and break oars in certain situations). You could then just have the ships turn on their center (lengthwise) hex’s facing, perhaps. Like a clock hand extending past it’s face.

I don’t have it with me; do your hex ranges for missile/siege weaponry track alongside Domains At War’s for that hex (company scale)? Could cheat a bit and have a second scale (like D@W Epic) for when the big ships come through, though you’d have some issues with movement rates (probably have to alternate 1 or 2 hexes per round)

I wasn’t a D@W backer, so I don’t have the hex ranges for that. All of the missile ranges were taken from the ACKS core book, by taking feet of range and dividing by 30 to get hexes, with the onager and ballista tweaked slightly to give them S/M/L instead of just a generic range.

As far as ship widths go, all of them are one hex wide ignoring the oars (even the deceres’ hull is no more than 8.5 meters wide, which is 28 feet). After watching some video of Olympias, I’m OK with all of the ships being one hex - I was adding the length of the oars to the width of the ship, but a lot of that length will be used vertically to reach the water, so the only real potential from interference should come from multiple deceres next to each other, which is just enough of a fringe case to not worry about. For turns, moving on the center hex looks like it will work, with the 4 hex ships turning on their second hex (so the aft swings further than the bow).

OK, tweak to firing arcs and weapon mounts:

Firing arcs are described by a pair of numbers. These numbers are facings that the weapon can fire into, starting with 1 being the hex face directly in front of the ship, progressing clockwise to 6 being the front left hex face. All arcs are described clockwise, so an arc of 5-1 means that the weapon can fire into any hex bounded by lines extending from hex face 5 (rear left) to hex face 1 (directly in front), including those lines.

Forward (F) - 6-2
Forward Port (FP) - 6-1
Forward Starboard (FS) - 1-2
Port Broadside (PB) - 5-6
Starboard Broadside (SB) - 2-3
Aft (A) - 3-5
Aft Port (AP) - 4-5
Aft Starboard (AS) - 3-4
Fore Tower (FT) - 4-2
Aft Tower (AT) - 2-6

Mounts: Any ship can mount 1 F or 1 FP and 1 FS, 1 A or 1 AP and 1 AS. Each heavy warship can mount 1 ballista each FT and AT. Any ship may mount any number of weapons broadside.

Ramming: A ram attack is carried out as an attack by a 0-level fighter, modified by the captain’s INT modifier. An attack from ahead or behind uses the target’s AC. An attack from the side subtracts the target’s length in hexes from AC (examples: A trireme is AC 5, 3 hexes long. From the side, it is treated as AC 2 for ramming attacks only. An armored deceres is AC 6, 5 hexes long. From the side, it is treated as AC 1 for ramming attacks only). A successful ram, in addition to the standard ACKS damage, also inflicts a Hull Holed critical on the target.

Onager update: due to the lack of a stable platform on a ship at sea, and because the onager fires indirectly (as opposed to the direct-firing ballista), all onager attacks have a -1 penalty to hit.

General siege weapon update: Siege weapons can only be fired at ships, not at individual targets. The critical hit tables will account for striking crew.

Critical Hit Tables:
2 - Left Rudder Destroyed
3 - Captain Hit
4 - Weapon Destroyed
5 - Oars Fouled
6 - Oars Destroyed
7 - No Additional Effect
8 - Marines Hit
9 - Marines Hit
10 - Rowers Killed
11 - Navigator Hit
12 - Right Rudder Destroyed

2 - Left Rudder Destroyed
3 - Captain Hit
4 - Weapon Destroyed
5 - Oars Fouled
6 - Marines Hit
7 - Oars Destroyed
8 - Hull Holed
9 - Hull Holed
10 - Rowers Killed
11 - Navigator Hit
12 - Right Rudder Destroyed

Critical Hit Effects:
Captain Hit - the captain suffers splinter damage
Navigator Hit - the navigator suffers splinter damage
Marines Hit - 1d4 marines suffer splinter damage. If there are multiple types of marines on board, 50% of the time the attacker chooses which type of marine, 50% of the time the target chooses which type of marine
Weapon Destroyed - 1 weapon is destroyed. 50% of the time the attacker chooses the specific weapon, 50% of the time the target chooses the specific weapon
Hull Holed - Target ship suffers a -1 turn rate (a turn rate of 1/3 becomes 1/4, etc)
Oars Fouled - Target ship suffers a -1 to speed for 1d3 rounds. Before rolling, the target can choose to reduce speed to 0 for 1 round instead
Oars Destroyed - 1d3 columns of oars are destroyed. If spare oars are not available, the ship is considered to have 1d3 fewer columns of rowers until spare oars become available. A bireme needs 2 spare oars per column, all other ships need 3 spare oars per column.
Rowers Killed - 1d6 columns of rowers are killed. Because oars are loosely tied to the ship to prevent rowers from dropping them overboard, they are not lost.

Columns of Oars: This is the total number of columns on board the ship. Half of the columns are on each side of the ship.
Bireme - 72
Trireme - 60
Quadrireme - 72
Quinquereme - 90
Hexareme - 110
Septireme - 128
Octeres - 148
Enneres - 168
Deceres - 190

If the active columns drop below 3/4, Sustained speed is reduced by 1 and Burst speed is reduced by 2. If the active columns drop below 1/2, Sustained speed is reduced by an additional 1 (2 total) and Burst speed is reduced by an additional 2 (4 total).

Note: I am adding these rules to my master document, so once the revisions are mostly done, a single post can be made with the updated rules.

Because I really shouldn’t assume anything - the critical hit charts are rolled on 2d6, and a critical is scored when a natural 20 is rolled to hit.

Just because I’d mentioned it, I thought I’d see how they compare:

Ballista – short range 5, medium range 10, long range 20
Onager – minimum range 5, short range 10, medium range 20, long range 40

At 30’ hexes (Domains At War Platoon Scale, platoons are 30 men or 15 mounted troops) ranges are:

D@W Ballista:

Light: Min 1, Max 16 hexes
Light, Repeating: Min 1 hex, max 16 hexes
Medium: 1-16 hexes
Heavy: 1-20 hexes


Light: min 10, max 20
Medium: min 12, max 28
Heavy: min 12, max 28

All Trebuchet: 12-32 hexes

Works out pretty similar!

There’s no range penalties in D@W; they also do a set amount of damage, but they’re stationary actors firing at stationary targets (fortifications) mostly, so artillery in that sense is more of a physics problem than an exchange of missiles.

Is splinter damage as per the damage dealt by the weapon?

For the critical hits, yes. It was an abstraction of the “damage to all creatures in a 5’ line” for the ballista and “damage to all creatures in a 5’ area” for the onager, but I didn’t define it thoroughly.

I’m also glad to see that the ranges mostly worked out. I wanted to have S/M/L so that they could be treated similarly to individual ranged weapons. The onager probably is a little bit long-ranged, but I haven’t had a chance to see how the combination of long range and poor accuracy (-6 at 21-40 hexes) actually works out.

New rule:
Initiative: Ships move on their captain’s initiative, with a +1 bonus for each time the captain has taken the Seafaring proficiency. Marines and weapon crews act on a separate initiative roll, with a bonus if the leader of the marines has ranks in Martial Strategy. (Note: if a campaign will focus on both sea and land battles, a Naval Strategy proficiency that functions identically to Martial Strategy but with MS specific to land and NS specific to sea may be prudent)

Clarification on firing arcs: broadside weapons may trace their line of fire from any hex that the ship occupies. F, FP, FS, and FT weapons trace line of fire from the front hex, while A, AP, AS, and AT weapons trace line of fire from the rear hex.

Topic for discussion: I am considering having a rammed ship forfeit its next movement and take a penalty to shots for one round to reflect the ship being shaken up. This would tie in to fleet rules, where initiative determines who moves first, with each “class” of ship moving before heavier ships, letting the light ships try to disrupt heavier ships by ramming.


I’m gonna fly off into some D@W stuff here, so please don’t think I’m giving you the business, though I may be “selling” D@W a bit here. I’m just showing what ACKS “will have” in a couple weeks or so that might be conceptually usable:

So, officers in D@W have a few characteristics that might aid here:

Leadership Ability: Equal to your # of henchmen you can hire - 4+ChaMod+Proficiency if any.

Zone of Control: 1/2 the Leadership Ability, representing the radius in hexes a commander may activate units without penalty (give them orders)

Strategic Ability: Highest of Int or Wis bonus, minus worst of Int or Wis penalty if any, then Military Strategy added to that. That determines your initiative bonus in mass combat for the commander’s units.

Morale Modifier: CHA plus any class powers (battlefield prowess, etc)

So, you gain a number of activation points equal to your Leadership Ability that you spend to activate your units. (it also determines how many divisions you can have in the army you command).

I could see splitting the marines and weapon crews into separate “units”, that can be activated in the particular order the captain wishes, with the ship perhaps counting as it’s own “unit” for movement.

Furthermore, each ship can be it’s own “division”, thus limiting any given captain’s fleet size to what he or she is able to handle.

Zone of Control could be reworked to reflect whatever the historical signalling method (and effective range thereof) was between ships of the time, perhaps with bonuses from the Signalling proficiency, or overload the Naval Strategy proficiency.

Separating Naval from Military, proficiency wise, is a really good idea; they are two different beasts. Make the PC that wants to be a terror on land and sea work for it.

Regarding the rammed ship effects: There’s the concept of “shock” in D@W, if a unit takes enough damage or magical damage; a morale roll determines effects (rout, flee, recoil, stand firm). That might be something worth modifying, since you’re already using a morale roll in several different places.

Pursuant to that, a unit can become “disordered”, requiring another Activation Point to use. If a successful ramming would cause each unit on board to have to roll for “shock”, and those units fail the roll, the captain perhaps wouldn’t have enough AP in that round to activate everyone on ship, and may have to forgo movement or marines firing or weapons firing depending on who failed, thus reflecting the on-deck disorder of a rammed ship.

Or do it for the whole ship.

Perhaps a critical hit (a particularly good ramming) (if you know what I mean) might also force the roll for the ramming ship in addition to double damage or what-have-you.

Completely random thought: is it worth the complexity to have a “warm up” to gaining speed, espc. from a stationary start? Perhaps using burst rowing to reduce the effect?

Quick reply to the non-D@W question: “Completely random thought: is it worth the complexity to have a “warm up” to gaining speed, espc. from a stationary start? Perhaps using burst rowing to reduce the effect?”

Not really. During the Olympias trials, they were able to get to their average sustained speed in three to four strokes, which is quick enough that I don’t see it being beneficial to have an acceleration limit.

For the D@W ideas, I wouldn’t be surprised if I end up doing a tweaked set of rules incorporating D@W ideas, so that there will be both an “ACKS core” naval rule and an “ACKS+D@W” naval rule. Unless, of course, Alex plans to have naval rules in a supplement, at which point I’ll just be modifying the heck out of them to fit my own feeling of how things should be done.

Huh. That’s interesting. I guess the number of oars; etc. Someone on the internet probably has the physics on it.

D@W: Alternatively, he may just publish yours. :slight_smile:

The Dark, would you mind dropping me an email at alex@autarch.co to discuss?

I do not currently have plans for naval rules but they are in hot demand. What I have read so far has been impressive and I’d like to further the discussion.

Alex - I’ve sent you an email from my gmail account.

Additional polyreme variations:
The standard polyremes described above are cataphract, multi-level ships. This means they have a full deck and have rowers on 2 (bireme) or 3 (all others) levels. However, this is not how all polyremes were rowed.

Aphract - this variation does not have a full deck, but narrow partial decks. This type of polyreme is somewhat lighter and thus faster and more maneuverable, but more fragile and with less room for artillery and soldiers.
Aphract modifiers: -10% shp (round to nearest 5), 1/2 marines, 1/2 artillery (rounded up), +1 turn (turn 1 round sooner), +1 crew morale when Burst rowing.

Single-level - this variation uses as many rowers as possible on the fewest number of oars. Archaeological evidence shows that up to 8 rowers could be placed on a single oar. This type of polyreme was wider than the multi-level polyreme. This gave it more deck space for marines and requires fewer trained rowers, but it was less maneuverable due to the wider hull. Technically, enneres and deceres with this modification are rowed on two levels (4 and 5 rowers for the enneres, 5 and 5 for the deceres), but the end result is the same.
Single-level modifiers: -1 turn (turns take 1 more round to complete), +50% marines, -1gp monthly maintenance per 2 rowers.

Time for a mildly fantastic addition to the rules:

Old warships can be converted to animal transports. As these ships are intended to be protected by warships, they carry neither weapons nor marines. However, they can carry one horse (or other horse-sized animal) for each marine they could normally carry. While the horses are larger than the marines, they are carried in slings without room to move around, allowing them to be carried closer to each other.

Flying transport:
Some nations that have both navies and soldiers who ride flying creatures, such as pegasi, griffons, or hippogriffs, have had the idea to combine the two for use as scouts and light combatants. Because these animals need room to move around, take off, and land, they cannot be stabled as close together as animals that are solely being transported. Thus, for each three marines removed from a ship, one flying animal and its rider may be added.

(non-rule author’s note: The potential number of mount-plus-rider pairs ranges from 2 for an aphract bireme to 45 for a single-level deceres. However, a wise captain will ensure he keeps enough marines on board to man the artillery. The ships that can fully man their artillery and fly the most creatures are the single-level octeres, enneres, or deceres, all of which can fly 16 pairs while still having a full group of artillerists)

Hot damn. Aircraft carriers.

I’ve got this dream of the biggest barge ever built launching rocs.

Ptolemy IV Philopator’s tesserakonteres (“forty”) might do it (for the giant roc, at least - the smaller ones could be used from existing ships). It was a catamaran hull (two “twenties” held together by a deck) that was 420 feet long, 57 feet wide, and on its trial run had over 4,000 rowers, 400 sailors, and 2,850 marines.

As a side note, I haven’t done up any ships larger than a deceres (“ten”) for a couple reasons. First, there’s fairly little information on them. Ptolemy’s beast is the only one I’m aware of with known dimensions. Also, there seems to be no evidence for any larger ships taking part in naval battles (although some may have participated in sieges).

That’s impressive. That’s only a little smaller than the first US carrier (converted from a different sort of ship), and about half the length of the first true carriers. For that matter, the small rocs have about the same wingspan as the late biplanes.

If I were to want to siege a coastal city, if I could weaken their navy first I’d certainly want to have engines on either side of the walls I’m trying to down. Just a good enough screen of smaller ships to protect what is essentially a mobile catapult platform.

Going back to my comment about the tesserakonteres being the only giant polyreme with known dimensions, if anyone has sources for any ancient or medieval (pre-gunpowder) ship sizes, I would appreciate it, particularly ones that mention length and beam and either draft or tonnage. The ones I’ve been trying to find information recently on are Chinese river warships and Imjin War ships, but good information on them is scarce (particularly after the rise in popularity of Zheng He thanks to Menzies’ work of historical fiction).