Rules Of The Mists

Ship Design

The chapter does not explain, how a spelljammer is physically built, as this is the province of master artisans of the World Of Mists. It does tell, how to create a spelljammer that works with the rules of the game from an idea. Throughout the process, two of the more common ship of the Oz'Nihead Cluster are used as an example. The sabre is a fast and manoeverable ship, which is often used as a scout vessel by militaries and is also a favourite of pirates. The Scarab-ship is one of the most common vessels, as it is durable and versatile.

Ship Design Basics

When beginning to create a ship, keep in mind the size limitation of the helms, making vessels longer than 24 metres impractical, as they need special devices for propulsion. The second basic thing to keep in mind is the basic conception and look of the vessel. Is it more like a ship, or more like a flying or swimming creature? Is its manoeuvrabilty provided by the rigging, by its wings, or something more alien? What standard size class is this ship? (Spelljamming vessels can be medium to colossal in size) What is its metrical tonnage? If it becomes larger than 100 tons, consider if You really want this vessel.

The Sabre is a ship-like vessel at first, but like all spelljammers its deck is lower over the water-line than that would be the case in a sea-going vessel. On the other hand, with its sabre-like wings (which give its name), it also resembles a bird if seen from above or below. The sabre has to be fast and manoeverable, so it will have a sleek build.

The Scarab-Ship is basically an upturned scarbaeus with its legs reattched on the wrong side, leaving the space, where the living beetle's lower side and deck would be open to be the deck. Inspite of its look, the scarab-ship uses a normal rigging, but only a single sail. The scarab-ship is a broad, somewhat clumsy ship, optimised for maximum space for its tonnage, rather than speed. It is the one of the staple civilian ship in the Oz'Nihead Cluster.

Manoeuvrabilty And Movement

All ships start with a basic tactical movment of three. (Most common ships areof Gargantuan size.) Small ships tend to be faster and big ships smaller. Additinally half the spell or manifester level of the helmsman is added to this number to get the actual tactical movment rate. The basic turning rate of any ship is one. No ship can have a turning rate of less than one. (See Space Combat for more details on tactical movment and turning.) The basic construction of the ship can change those ratings in various ways. Slender ans small ships tend to be faster, while thicker and bigger ships tend to be slower (and more clumsy). Another important factor to keep in mind when thinking of manoeuvrabilty is the rigging or the wings. All costs given here exclude the Spelljamming Backbone and the Spelljamming Helm

Crew: Standard rigging or wings require eight sailors to use properly. Each level of Rigging and wings also doubles the crew required to use it. If there is not enough crew, the rigging or wings fall to the next lower level. Example: A ship with level 2 rigging requires 32 crew to move at full manoeuvrability. If it has only 20 sailors assigned to the task, it works as a level 1 rigging instead.

The Sabre is a long and slender ship, 20 Metres long and only four metres wide and is of Gargantuan size. It has a basic TM of 3, +2 for its length-width ratio, giving the ship a base cost of 11,000 GP. It currently has a TR of 2, but that is not enough for its makers, so they increase the wing level from zero to one, giving it a TR of 1 and a current price of 14,000 GP. 16 crew are required to manoeuvre the ship at full TR.

The Scarab-Ship is a thick-bellied ship, optimised for maximum enclosed area. It is 15 metres long, 7 metres wide and of Garagantuan size. It has a basic TM of 3, -4 for its length-width ratio, making for an effective result of 1, as no ship can have less basic TM than that. It also has a basic turn rating of 2, due to its size. The Scarab-Ship is a large vehicle able to carry a lot of people, so it is usually delivered with level 1 rigging, giving it an effective TR of 1. It costs a base 10,000 GP for its size -20% for its length-width-ratio for 8,000 GP. It adds 2,000 GP for the rigging for a total of 10,000 GP. The rigging requires 16 crew to provide its advantage.

Structural Integrity

Structural integrity (SI) defines the stability of a ship against hostile environment and in battles. While the hull protects the cargo and the crew, the structure keeps the ship itself together. There is only so much punishment, the ship can take, before it breaks apart, but usually crew and / or hull give in first, as most combat spelljammers are built with stability in mind. The SI can be increased, be making the structure of a tougher material, or by creating a more resistant construction (e.g. by increasing the number of "ribs"). Weight is not usually an issue. Space is the problematic ressource for spelljammers.

The Sabre is made from wood, but to make it tougher, it has a soft metal backbone, adding 80 x 100 GP to its price. Now it costs 22,000 GP. Its SI rating is 3*80 = 240 points.

The Scarab-Ship is made from wood, so is its backbone. It is a large ship, so the makers don't mind the interior space loss coming with double strength backbone. It gives the ship an SI rating of 2 x 100 = 200 points. Its cost is now 12,500 GP.

Hull Strength

The strength of the hull is mostly determined by its material. Usally the hull has at least ten times as many hit points, as the ship has SI. Except for the thickness, there is litte in the way of construction to be done to make the hull stronger. Standard hull thickness is four inches. A ramming attempt has to deal enough damage to break one section of the ship's hull, to successfully penetrate.

The assumed hull thickness in the table above is four inches of material. If a ship uses thinner or thicker hull, divide the number of hit points by four and multiply by the new number of inches. (I know that the values do not fully add up with table 8-12 from the Player's Handbook Chapter 8. Assume that this table is for materials specially treated for ship building, if it worries you.)

Ship Hit Points: A ship has has an overall number of hit points equal to the number of tons multiplied by the hit points of each hull section, divided by two, or ten times its structural integrity, whichever is higher.

The Sabre is a light duty scouting ship, so it is only fortified with hard wood. It has 80 tons multiplied with 75 hit points per section, divided by two for a result of 3,000 hit points. Its price increases to 22,400 GP.

The Scarab-Ship is not the fastest vessel around, so it is made with staying ability in mind. Its hull is three inches of hard wood, covered by one inch of metal plating, giving its scarab-like appearance. Its hull costs 15 GP per section. (5 GP for the hard wood, plus 10 for one inch of Steel. Any part of hull plating cannot be less than one inch thick.) It uses the hardness of Steel. The number of hit points per section is 55 for three inches of hard wood plus 35 for one inch of steel, for a total of 90 hit points per section. Its 100 tons multiplied with 90 hit points, divided by two gives a result of 4,500 hit points, making it a quite durable vessel. It now costs 14,000 GP. (plus 15 x 100).

Weapons

Most spelljamming ships are armed with several siege weapons, which can either be mounted directly (and fire only in one direction), or they can be mounted on a turret, so that they cam be aimed in a number of directions. Weapons cannot usually fire over their own ship (at least without damaging it). The major ranged attack for spelljamming vessels is magic, which is generally far more precise and does more damage than any of those weapons. The wizards (and priests and psionicists) are or course also needed to man the helm and provide the ship's speed and manoeuvrability.

Siege Weapons: A spelljamming ship may mount catapults and ballistae, as described in the DMG pg. 99-100. All of those weapons may be mounted immovable, or on turrets, allowing them limited flexibilty to cover a wider range. Aiming a catapult in space is easier, because the rock flies in a straigh line, once it leaves the ships atmospheric envelope. The AC of a target ship is 10 plus the ships TM, plus the AC modifier of its hull material. Ship siege engines are generally a bit easier to use and load than land-based siege engines, because they are permanently mounted. Ship siege weapons can be crafted in masterwork quality and even be magically enhanced.

Rams: Most spelljamming ships are equipped with a ram. As these ships do not sail the sea, holes in the hull are generally less problematic, but ramming still deals a massive amount of damage, but unfortunately it also endangers the own ship. Any ramming manoeuvre deals half its damage to the ramming ship. Using a ram does cause structural integrity damage. The most common rams are piercing, bludgeoning and hollow rams. Clever engeneers may have come up with other shapes or additional tricks. The prices geven below include the strengthening of the prow to keep some of the ramming damage from the ship. A ram does one dice of Damage per ten tons of ship size. The coxswain or helmsman have to do a reflex save with the base DC below, or the ram is stuck in the target ship. It will take 1d6+4 rounds at least to get the ship free.

Magic: Spells with close range can only be used on board and during buarding actions. Spells with medium range reach three hexes + one hex for every three caster levels. Spells with long reach have a range of five hexes + one hex for every two caster levels. Fire spells are always have their point of origin focused on the caster when used in the phlogiston, doing +50% damage.

Crew Sizes

A spelljammer needs at least enough crew to man the rigging or wings, a captain, a navigator and three helmsmen to be fully operational. A ship can move through space with less crew, but it will only have limited capacity and may easily become prey to pirates or space creatures. The fighting crew adds the number of people necessary to man its siege weapons, but does not include extra fighting forces for boarding (marines). The maximum crew is the number of people a ship can carry, so that its atmosphere will last three months.

Minimum Crew: The minimum crew depends on the level of the rigging (or wings). Both sample ship need sixteen crew to manoeuvre their ship, plus three helmsmen, plus a captain (who can double is navigator). Giving both vessels a minumum crew of 20.

Fighting Crew: The fighting crew depends on the number and kind of siege weapons mounted on the ship, which is decided for each construction individally. A ram does not require special crew to maintain. Let us for now assume, that our sabre has two medium catapults and two heavy ballistae. Those weapon take eight people to use, giving it a fighting crew of 28. The Scarab-Ship is usually armed with two heavy catapults, giving it a fighting crew 26 people.

Maximum Crew: A spelljammer can carry one medium size person per ton of size without detrimental effects on how long its air envelope stays fresh. Construction requirements, such as the need for cargo space may further reduce the number of people, a ship can carry in decent conditions. Crew quarters are generally quite crammed, only the higher officers (captain, 1st lieutenent, navigator) usually have a bit more space. Most spelljammers have a special cabin, where mystics can meditate and prepare their spells or psionic powers.

Finishing Touches

Now that the vessel's combat and flying capacity has been determined, there is time for the final pieces of design. The tonnage of a ship is usually determined by multiplying its length with its width and subtracting roughly five percent for the rounded parts, usually rounding a bit to get a number ending with 0 or 5, but you already knew that. Most ships built for space are quite flat. The tonnage of a ship describes its enclosed area, generally excluding the rigging or wings.

Interior Space: The interior space is equal to its tonnage minus 10% for the hull and backbone. That is a sabre has 72 tons interior space and a Scarab-Ship has 85 tons of interior space (loss of another 5% due to the double strength backbone). Crew quarters take up at least one ton per person, with a minimum of eight tons for a single cabin. A scarab-ship usually has 40 tons of crew space (for 36 people) and 45 tons of cargo space (which is further reduced by its weapons). A sabre usually has 40 tons of crew space, also for 36 people, leaving 32 tons of cargo space, which are often further reduced by weapons and to make space for more people on board.

Magical Backbone: Far more expensive than the physical constuction of a ship is the magic required to make it fly in space. The magical backbone costs 100,000 GP for the sabre and 120,000 GP for the Scarab-Ship. See The Spelljamming Backbone for more information.

Spelljamming Helm: Both ships are large enough to require a major helm for propulsion, adding another 200,000 GP to the cost of both ships. The Sabre as presented costs 326,400 GP. The Scarab-Ship costs 317,000 GP.