Agility Rules

Those of you who have played Ironclads and Ether Flyers have surely noted that: "If small, fast naval ships get defense bonuses for being difficult to hit, why don't Aerial vessels, which are generally both smaller and faster?"

You're right, of course; these small gunboats are supposed to be difficult to hit; in fact, that is a primary startegy in their design. Why then are there no rules to accomodate this?

Well, a defender of the current SKY GALLEONS OF MARS might say that weapons on board such aerial vessels are designed to track and sight such nimble craft.

Well... maybe.
Nevertheless, it still ought to be easier to hit a large vessel than a small one; smaller ships get no advantage and a small swarm of ships can sometimes be picked off one by one by a large ship that they are swarming, while the large ship's reserves of damage allow it to withstand the group attack. Such things make the notion of a knockdown dragout fight more effective than trying to use clever tactics.

Well, these rules will hopefully straighten this out a little bit, and perhaps give that Aphid a little more needed oomph the next time it goes up against that pesky Fenian Ram.

The Rule

The rules for Agility are meant to be fairly simple. The first step is to calculate a ships Agility Rating. Note that this rating is based on a ship's speed and may vary throughout the game.

The Base Agility rating for any ship is zero, and a ship has an agility rating of zero unless it meets the requirements for another rating.

Positive Ratings

  1. A ship with a speed greater than it's size rating has an agility rating of one.
  2. A ship with a speed greater than twice it's size rating has an agility rating of two.
  3. A ship with a speed greater than three times it's size rating has an agility rating of three.

    This list could concievably go on even more, if a GM allows, though this system is not really meant to use numbers higher than three.

  4. A ship with a speed greater than five times it's size rating has an agility rating of four.
  5. A ship with a speed greater than eight times it's size rating has an agility rating of five.
  6. A ship with a speed greater than twelve times it's size rating has an agility rating of six.
Well, you get the idea.
Anyway, a positive Agility rating is meant to indicate that a vessel is difficult to hit, and that guns firing at it have a harder time tracking it. But it is possible that ships may be easier to hit because they have stopped or are large and slow-moving.

Negative Agility

  1. A ship with a size greater than six times it's speed has an agility of negative one.
  2. A ship with a size greater than twelve times it's speed has an agility of negative two.
  3. A ship with a size greater than twenty-four times it's speed has an agility of negative three.
Once again, you get the idea. Ships that are big or slow or both will be easier to hit.
To calculate the agility of a ship that is not moving at all, treat it's speed as being equal to a rating of 1. Then subtract one from the agility rating that is thus generated.

Ah, but we're not done yet. The agility rating is not simply a penalty/bonus for firing at enemy ships. It must be first compared with the firing weapon's Traverse rating. Never heard of that? Well, that's OK; it's on the updated gun list also posted on this site.

The Traverse rating of a weapon represents the ability of the gun to swivel back and forth in order to track fast-moving targets. Small rapid-fire weapons tend to have high traverse, while large heavy weapons cannot be moved easily, and so have a low, often negative Traverse.

If the target is at long range, then a weapon's traverse is considered to be one higher, since the target will be easier to track at a distance (the weapon does not have to swing as far to be brought to bear), though still more difficult to hit in the long run.

To Hit Bonuses and Penalties When comparing the Agility of a target and the Traverse of the firing weapon, two possibilities occur:

  1. If the Agility of the target is positive and the weapon's Traverse is less than the Agility rating, then the firer has a penalty to hit of one (or -1).
  2. If the Agility of the target is negative and the weapon's Traverse is more than the Agility rating, then the firer has a bonus to hit of one (or +1).
That's basically it. A high Agility never grants a defensive bonus of greater than one, and only if it exceeds the weapon's Traverse rating. Likewise, a negative Agility never grants the attacker a bonus of more than one, and only if a weapon is nimble enough to exploit it. If a craft has a positive Agility, but a weapon's Traverse is higher, then that weapon does not gain any bonus to hit; it simply negates the defensive bonus given from having a high agility. Likewise, a vessel with a negative Agility does not gain any defensive bonus if a firing weapon's Traverse is even lower. A negative Agility provides a bonus to hit or nothing at all.

A Few Other Optional Rules

Raking Fire

In the era of wooden fighting ships and smoothbore cannons one thing that was greatly feared by the fighting sailor was something called Raking Fire. Raking Fire is simply any shot fired at a vessel from the front or rear.

Why was raking fire so feared? Well, any shot fired at the side of a ship had only a relatively short distance to travel after penetrating the hull, before leaving the vesel again. On the other hand, a shot fired from the bow or stern of a vessel could plunge all the way from one end of the ship to the other, causing great havoc to anything it touched, which would be a great deal more than if the ship were facing broadside.

Imagine that you are bowling, and experimenting with the layout of the pins. If you simply stretched a bunch of pins horizontally across the bowling lane you would be lucky to strike more than one or two. On the other hand, if they were all lined up pointing at you, striking the lead pin might knock them all down.

Therefore, the raking fire rule is this:
If a vessel is in it's target's bow or stern aspect, then the shot is considered Raking Fire.
Raking fire shots are made at a penalty of -1 to hit.
However, should a raking shot hit, the hit location roll is made normally. Should the shot hit an unarmored location, or penetrate the armour of an armoured location (i.e. the Penetration rating of the gun is equal to the Armour rating encountered), then a second hit occurs as well, and a second hit location is rolled.

The possibility of scoring double hits should more than compensate for the loss of ability to hit, particularily at close range.


This is not so much a rule as a common sense addition to record-keeping.

Any time a ship form is made out for a steam-powered vessel, a separate set of boxes shouls be marked off for an entry called "Endurance". For each day of Endurance the ship possesses, include one box. Thus, for campaign games, each day a ship travels can be recorded by marking off a box on the endurance entry.

For steam vessels there is usually plenty of room in the "Maneuver" section of the ship record sheet; rarely are more than one row of Engineers needed.

Optionally, in a campaign game you may include the possibility of the coal bunker of a ship being hit, and some coal being lost. Each time a hull hit is scored on a steam vessel, and the damage value of the weapon scoring the hit is equal to or greater than the hull size of the struck ship, roll a d6. If the result is a 6, then a point of endurance is lost, as a hole has been ruptured in the coal bunker.

If the vessel is at long range, or is being fired at from below, the number needed on this die to determine if the coal bunker is hit is 4 or higher. However, if half or less of the vessel's endurance remains, then a second D6 roll must be made. If the result is 1 to 3, then an empty portion of the bunker has been hit, and no Endurance is lost. Otherwise, the same rules apply. More meticulous GM's might assess the remaining amount of coal and divide it into 6, thus figuring out what chance in 6 the shell or shot has of hitting a full coal bin.

Extreme Range

Weapon Afficionados may have noticed that the ranges for rifled weapons seems rather short, compared to the actual ranges of such weapons. Large-bore weapons such as the 8" and 14" guns had maximum ranges expressed in miles, and a dreadnought generally had armament capable of hitting targets on the horizon, though not necessarily with any accuracy.

Sky Galleons of Mars weapon ranges represent the ability of weapons to hit targets accurately, though such weapons can throw shells much further. However, successfully striking a target at that distance can take work.

On the Updated Gun List there is an entry for "Extreme Range" for most large-bore rifled weapons, generally those with a ROF of less than 1. This is marked by an (E) column next to the Range column. This is the value in hexes that represents the Extreme Range of the weapon.

This is meant to offset the grievous disadvantage given to such weapons. For example, under the original rules, an 8" gun weighed 300 tons, had a ROF of (1), and a damage rating of 8. In other words, firing every other round, the average damage per round dealt by an 8" gun is four. Meanwhile, since a 6" gun weighs only 100 tons, three of these weapons could be installed in place of a single eight inch gun. And since the damage value of a 6" gun is 6, and they fire every round, the average damage per round of these weapons put togeter is 18, over four times the value of the single 8" gun. Which would you choose for your ship?

Anyway, a weapon with an Extreme Range rating may fire at targets that are within this range. However, to hit a vessel at this range, the attacker must first make a roll as if the target were at Long range. However, this first roll is made to determine if the shell has landed in the same Hex the target is in.

Should the shell land in the correct hex, then a second roll is made, with the same chance to hit as the first, to determine if the target has been hit. If this roll is a success, then proceed normally with the hit procedure. If this roll is not a hit, however, then other targets in the same hex may potentially be hit. If there is more than one potential target, determine order randomly, and make a to hit roll for each target until a hit is generated.

Should the shell fail to land in the correct hex, then the Hex that the shell lands in must be determined. First, the distance away from the target hex must be determined; make another roll, and consult the following table. The only modifiers for this table allowed are the Crack +1 and Green -1 crew modifiers.

Distance Table

  1. - 3 hexes away
  2. - 2 hexes away
  3. - 2 hexes away
  4. - 1 hex away
  5. - 1 hex away
  6. - 1 hex away
The distance that results will create a ring around the target hex, from which a specific hex must be selected. Since each possible ring has a number of hexes divisible by six, it should be easy to randomly determine which hex of these is hit by the shell.

If any targets are present in the hex, then the routine for randomly hitting the targets therein is followed as if the targets were in the same hex, above.

Obviously, if the scenario has no secondary targets present, such as a one-on-one ship duel, the whole issue of a miss can be ignored, since there are no potential secondary targets that might be hit.

Long Range Penetration

Rather than have two listings for Penetration (one for short range and one for long), the original game had just one rating. Instead of having two separate ratings, it is much simpler to have a single rating (see Updated Gun List) and double the armour rating of a target for all weapons fired at long range. Remember that for the purposes of armour, a rating of zero is considered to be half of a rating of one, and double the armor rating of a vessel with a rating of zero produces a result of one. However, since a shell fired at target at a lower altitude has the benefit of gravity assisting the velocity of the shell, do not double the Armour rating of a vessel at long range if it is at a lower altitude than the firer.

Ramming Speed

Since the momentum of objects depends on not only their mass but their speed, and since the momentum of a vessel is what causes damage in a ram, it makes sense that a faster vessel will do more damage in a ram attempt than a slower vessel of the same mass.

To calculate the damage done by a ramming ship, first divide the vessel's speed by 6. Then multiply this fraction (which will be 1 if speed is 6, if speed is 3, and so on) by the vessel's Hull Size, rounding to the nearest . This is the damage rating of the vessel in a ram. Note that vessels with a speed of 3 will have the same damage as from the original game, but vessels that are faster will have a higher proportion of their Hull Size in ram damage.

Heated Shot

Heated Shot was a feared weapon in the eras of wooden sailing vessels. Essentially a lead shot could be heated before being fired to the point where it would ignite wood that it came into contact with on the target vessel.

Heated Shot was a rare tactic only because of the facilities required to use it are intensive. A gun emplacement that intends to fire heated shot must posess a furnace and therefore can never be located on a ship. Likewise, Ordinary gun emplacements and pillboxes are too small to hold the kind of furnace that is required. Only fortresses will be able to make use of heated shot, facilities that possess enough room in their confines to house a large funace and workshop.

When a gun firing heated shot scores a hit on a wooden vessel or kite, a separate roll is made to determine if a fire has started. Roll 1D6, and compare this number to the damage value of the firing gun. If the roll is higher than the damage value of the gun, there is no effect. If the roll is less than or equal to the damage value of the gun, then a fire of level one has been started on the vessel. If the damage type scored by the gun hit is a fire, then this roll is always considered to succeed. The one point of fire is added to the regular gun damage (they don't create two separate fires).

Heated shot is less effective against metal-hulled ships (except kites). Against a non-kite metal hulled vessel the roll to see if an extra point of fire damage is scored only occurrs if the gun has already scored a fire hit. If this is the case, and the roll succeeds, then one point of extra fire damage is added to the gun's damage.

Fortresses capable of firing heated shot do not keep their furnaces constantly ready as this incurs great expense and amounts of coal. When an enemy is sighted by a fortress and the commander of the fortress can order his furnaces lit. If so, on each turn the player controlling the fortress rolls a D6 to determine the readiness of the furnaces. If a 6 is rolled, the furnace is lit and smoke will be visible coming out of the chimneys of the fortress. If another 6 is rolled, the furnice is at full blast and any shots taken by guns in the fortress after that turn may use heated shot. If the gun crews of the fortress are green, then a third '6' must be rolled before the furnaces are at full blast, while if the crew of the fortress is crack then the guns may fire the heated shot on the same turn that the second '6' is rolled.

It is possible that a fortress will have its furnaces ready if it anticipates or is warned of a battle in advance. More likely in such a circumstance the furnaces will be lit but not at full-blast yet, requiring only one '6' to be rolled.

Note that only guns firing solid roundshot may fire heated shot. Heated Shot has no effect when using grapeshot or on Rod Guns, and can never be used with guns that can fire shell or shrapnel.