SOL CRUISER

v. 1.01
(changes from v. 1.0 are in italics)

 

SCALE

Each ship counter represents one actual ship. Each fighter and missile represents 4 fighters or missiles. One hex equals 10,000,000 kilometers, one turn is 18 hours long, one thrust point represents a .2G acceleration sustained over a period of 18 hours, and speed of 1 is about 150 km/sec.

TURN SEQUENCE

1) Detection Phase. Carry out detection attempts, as described below.

2) Detected Ships' Movement Plotting Phase/ Launch Phase

3) Undetected Ships' Movement Plotting Phase/Launch Phase

4) Intercept Phase. Determine Intercepts, as described below.

5) Combat Phase. Resolve Combats, as described below.

6) Movement Phase. Move all ships to their final locations.

DETECTION

A ship is considered to be detected if the distance between it and the detecting ship is not greater than the detecting ship's Sensor Rating + Crew Quality (CQ) Rating, multiplied by the target's Signature Rating. All fractions are rounded up.

Sensor, Signature and CQ ratings are all found on the ship's status sheet. Signature rating is further modified by the target's ship's speed.

At Speed of 0, Signature is reduced by 1. 1-2: -.75, 3-4: -.5, 5-6:-.25, 7-8: 0, 9-10:+.25, 11-12:+.5, 13-14: + .75, etc. Treat ships with final signatures lower than .25 as having a signature of .25.

Ships detected are visible to all and may be attacked by all. Undetected ships may not be targeted at all. Missiles are considered to be automatically detected.

PLOTTING MOVEMENT

Each ship has a thrust rating, from 1 to 5. To change speed/heading, find the current destination hex, and pick the new destination hex, with the distance between the two hexes no greater than the thrust rating. For each hex of distance between the old and new destination hexes, the ship is considered to have expended one thrust point.

Ship course is recorded using the following notation. Direction is denoted with letters, clockwise from the front, with A being toward the top of the map (this should be agreed upon during game setup). To note the ship's course, find the shortest path between ship's location and its destination hex. For example, a ship moving directly toward the top of the map with a speed of 10 would have have a course of A10. A ship not moving directly along a hex row might have a course noted as A5 B6 (or B6 A5). This means that to locate the ship's destination hex, first move 5 hexes in direction A, then 6 hexes in direction B. The ship's course is considered to be a straight line connecting the centers of initial location hex and destination hex. On the ship's status sheet, record the ship's speed by adding up the component vectors. A ship with course of A5 B6 would have speed of 11, for example. Also record the ship's thrust for this turn (how many thrust points did the ship expend). Since visualizing course vectors may be rather difficult, especially when several ships are in play, it is recommended that players use a mapsheet which permits course vectors to be drawn on it with erasable markers, grease pencils, or even regular pencils.

Undetected ships all must plot their movement simultaneously. Detected ships plot movement according to their Initiative (Thrust + Crew Quality), in ascending order. The only exception is that at the end of the detection phase a player may declare any and all of his ships/missiles to be "In Pursuit" of any detected enemy vessel. Movement for pursuing ships/missiles is plotted immediately after pursued ones, regardless of their Initiative ratings.

Vehicles are launched in the starting hex of ship's movement, and have the same initial vector as the launching ship. They may change their vector in the turn they are launched using their thrust.

INTERCEPTION

An Interception may take place if two or more ships' courses intersect. It is automatic if each side is trying to intercept the other. If both sides are trying to avoid the other, it automatically fails to happen. If one sides is trying to intercept, while the other is evading, use the following formula to determine whether the interception is successful. No intercept attempt may be made against undetected ships/missiles.

The intercepting ship rolls 2d6-2. On a roll of 6 or greater, the interception is successful. Following modifiers are used: if intercepting ship is faster, add the speed difference/2. If it is slower, subtract the speed difference/2. If intercepting ship used more thrust this turn, add thrust difference x 2. If it used less, subtract the thrust diff. x 2.

If more than one ships/missiles attempt to intercept the same enemy ship in one turn, each successive's attempt die roll is modified by 2. For example, the first missile salvo would not get any modifier, but a second one attempting to intercept the same target would get a +2 mod, a third one a +4, etc.

Intercept rolls are also modified by CQ rating. Add CQ of intercepting ship, subtract CQ of intercepted ship. For missiles, use CQ of controlling ship.

COMBAT

After all interceptions have been determined, combats are resolved. If more than one ship/fighter/missile flight has intercepted the same target, determine the order in which interceptions took place, and resolve combats in that order.

Ships are armed with a variety of weapons, including ship-mounted energy weapon batteries and detonation laser warheads carried by missiles and submunitions. All fire (by beam batteries and detonation warheads) takes place inside one hex, and only against detected, intercepted/intercepting enemy units. Ships may fire any and all weapons against valid targets, but each beam battery can be fired only once per hex of movement (in other words, if a ship intercepts or is intercepted more than once during a single turn, it may fire beam batteries in each resulting combat, provided they happen in separate hexes). Detonation laser warheads are single-shot weapons–once one is detonated, it is removed from play. There are no firing arc restrictions, missile and submunition launch penalties. All missiles and submunitions may be fired simultaneously, if owning player so desires.

Beam Battery Attacks:

Roll a 2d6-2. On a roll of 1-3: Miss. 4-6: 1 hit, 7-9: 2 hits, 10-12: 3 hits, 13-15: 4 hits, 16-18: 5 hits, etc.

Modifiers used include target Size x 3 (from status sheet), CQ x 3 of the firing ship, and closing speed. If the ships are moving toward each other, Closing Speed is the sum of the two ships' speeds. If one ship is moving roughly perpendicularly to the other, use the higher of two speeds. If one ship is overtaking the other, use the difference of two speeds. The faster the ships are closing with each other, the less time they will spend within the range of the opposing ship's weapons, which will reduce number of hits. Detonation laser warheads do not suffer from that limitation, since they fire their shots all at once.

Closing Speed modifiers: CS 0: +15, CS 1-2: +12, CS 3-4: +9, CS 5-6: +6, CS 7-8: +3, CS 9-10: 0, CS 11-12: -3, CS 13-14: -6, etc.

Beam fire is also affected by armor protection and penetration values. There are 5 levels of protection and penetration: Unarmored (Un)(protection level only), Light (Lt), Medium (Med), Heavy (Hvy), Very Heavy (V. Hvy). When a beam battery fires at a target with lower armor level, it gets a +3 to hit modifier per each level of difference, when it fires at a target with the same level, it gets a +0 mod, when firing at targets with higher armor protection, it gets a -6 mod per level of difference.

Fire Control Modifier: 2300AD recognizes 3 tech sub-levels (NM, OM, and OC–see Ship Construction for explanation). Ships get a +3 modifier per level higher than the target ship and a -6 modifier per level lower than the target ship, respectively. This represents the relative ability of more sophisticated fire control systems to overcome ECM, etc.

While undetected ships may not be intercepted and fired upon, intercepting ships/missiles may be subjected to return fire even if they are undetected. When firing at an intercepting ship/missile which was marked with a Detected marker, apply the following modifier:

Target ship's sensor value 1-6: -12
Target ship's sensor value 7-12: -9
Target ship's sensor value 13+: -6

Missiles are considered undetected if they were launched on the same turn from an undetected ship.

Beam Battery Damage: Lt batteries inflict 1 point of damage/hit, Med–2 pts, Hvy–3 pts, V. Hvy–4 pts.

Detonation Warhead Attacks

Instead of rolling on the to-hit table, roll as many d6 for each warhead damage dice. This is your number of hits. The hit roll is modified as follows:

Armor: +1 to the roll per each penetration level higher than armor level. -2 per each penetration level lower than armor level.

ECM: +1 per tech level higher than target, -2 per each level lower than target.

Size: add/subtract size modifier.

Detonation warhead damage: Lt inflict 1 damage point per hit, Med 2 pts, Hvy 3 pts, Vhvy 4 pts. Detonation warheads may attack only once and, unless carried as submunitions, their detonation also destroys the carrying missile.

Firing At Missiles and Submunitions

Missiles and Submunitions may be fired on by beam batteries (all beam batteries may fire point defense, regardless of size) and submunitions. Missiles may be launched against incoming missiles (but not submunitions) only if the missile is detected following ordnance launch. Incoming missiles must still be successfully intercepted before they can be engaged with own missiles. Missiles have signature of .5 (modified by velocity), and must be successfully detected if they are to be engaged. Submunitions are automatically detected if their launching ship has been detected.

Missiles and submunitions have a Size Modifier of -2. Missiles and Submunitions are unarmored, but no armor/penetration-based to-hit modifiers are used when firing on missiles.

A beam battery, if it scores several hits, may allocate them between several incoming missile/submunition flights. Detonation warheads (both submunition and missile-based) must attack a single incoming submunition/missile, and may not distribute their hits.

1 hit on a missile/submunition destroys it completely. Fire on missiles/submunitions is resolved before the missile/submunition attacks the target vessel.

DAMAGE

All ships are rated for damage points. When damage points are inflicted, cross off damage points off on the ship status sheet, beginning with the top row. After the each row's damage points are crossed off, conduct a threshold check. Damage is applied immediately after combat, before proceeding to resolving next intercept. However, if several ships or missiles attack one ship and all the combats take place in one hex, all of these combats are treated as a single combat and damage effects are applied after all combats have been resolved.

Roll a d6 for each beam battery, missile, submunition, on-board infantry company, fighter flight, row of thrust points still remaining on the ship (Exception: fighters roll only for weapon systems). After the first row, a system is destroyed on a roll of 1-3, 2nd row: 1-4, 3rd row: 1-5. After all four rows are marked off, the ship is destroyed.

Threshold checks also include stealth, armor, propulsion and sensor systems. Each of those systems is eliminated after two failed threshold checks. The first failed threshold check reduces that system's performance by 1/2. Destroyed propulsion system means the ship may no longer alter its course, destroyed sensors means it can no longer detect ships, though it may still engage detected enemy ships. Armor and stealth levels are lost at a rate of 1 per failed threshold check.

To simulate damage control efforts, threshold checks are modified by the CQ value.

MISCELLANEOUS RULES

Crew Quality (CQ): Each ship is rated for crew quality. There are 5 CQ levels, and their modifiers are: Green -2, Trained -1, Regular 0, Veteran +1, Elite +2.

Remote Object Control Radius: Remote Objects (missiles, reconnaissance drones, other unmanned spacecraft) have a limited control radius. At NM, the radius is 25 hexes, at OM it is 15, at OC it is 10. For a remote object to remain under control there must be a friendly ship no smaller than 500 cu. m. or a fighter craft capable of carrying missiles within that number of hexes of the remote object at the end of turn. Missiles which go out of control are removed from the game. There is no limit to the number of remote objects that may be controlled by a single vessel.

Docking and Entering Hangars: To dock, ships must perform an Intercept with CS of no more than half (round fractions up) the higher thrust rating of the two ships. Ships entering hangars are considered to have entered by the end of the turn. Docking may be used to refuel ships/fighters/missiles, etc. Vessels being refueled are considered refueled at the end of the turn in which they dock and may be relaunched at the beginning of next turn.

Stacking: 10,000,000 kilometers is a lot of space, so there are no restrictions on the number of ships which may occupy the same hex. An opposing ship may attempt to intercept only one of several ships co-located in a hex, and the remaining ships may not fire on that ship unless they succeed at their own intercept attempts of that ship. Missiles targeted against one ship may not be engaged by weapons of another ship in the same hex.

Goalkeepers: The only exception to the stacking rules is the "Goalkeeper Rule": a ship may be designated as a "goalkeeper" for another ship and fire on ships and missiles which intercept the protected ship. Only one goalkeeper may be assigned per ship. Ships acting as goalkeepers may not be assigned goalkeepers of their own. Ships assigned a goalkeeper may not act as goalkeepers themselves. Goalkeeper and protected ship must have the same course, and must start and end movement in one hex. Fighters and beam-battery armed missiles may be used as goalkeepers, but detonation missiles and submunitions may not.

Planets: Ships whose course passes through a hex adjacent to a planet have their end hex moved by one hex to the upper right (relative to the ship's heading after entering the destination hex) if the planet was passed on the left, an to the upper left if on the right. Ships whose course passes through a planetary hex crash. Ships may enter orbit if their speed is one and their end hex is a hex adjacent to a planet. While in orbit, ships may remain in one hex, or move around the planet in either direction, in which case they have a velocity of one and a course which leads into the next orbit hex. All ships in orbit are considered to be in the same hex and to have speed of 0 for the purpose of combat and detection. Ships in orbit have their signatures reduced by .25, or by .5 if orbiting a gas giant.

Stars may be orbited as well, but only by ships with Heavy or Vheavy armor. Signatures of ships orbiting stars are reduced by 1.

Towing: it is possible to tow a disabled ship. In order to establish a tow, the two ships must first dock. Recalculate the towing ship's thrust rating to account for the extra mass.

Interstellar Travel: All Sol Cruiser ships with volume of 500 cubic meters or greater may be equipped with an FTL wormhole drive. Its mass and volume are already factored into TNP drive costs. In order to engage a drive, the ship's destination hex must be within 5 hexes of the map's edge (considered to be the G threshold for a successful jump) and the ship must not make any course changes, fire any weapons, launch or recover any remote objects during this turn. Doing so interrupts the wormhole drive's process of locking on to the destination star system. Maximum wormhole jump distance is 7.7 light years, although work is being done on extending that limit. Between-system travel time is directly proportional to the velocity with which the ship travels in the last turn before the jump (more details on that later). Wormhole system's lock-on cannot be detected on the far end–the first indication of an impending jump is the ship's appearance in-system. Ships may not be towed into a wormhole jump, but may be carried aboard in hangars and bays.

SHIP DESIGN RULES

SHIP DATA


Notes

Sol Cruiser started out as a space combat game for the 2300AD "prequel" ("2300 AD Episode One: The Unplayable Menace") which is going to deal with Earth and solar system exploration prior to the discovery of stutterwarp. Hence the name of the game. However, while I am still working on the "prequel", I came to the conclusion that the Sol Cruiser system could be just as successfully applied to the "regular" 2300AD setting, and become an alternative space combat set of rules.

Most "new" rule sets usually owe something to already existing ones, and Sol Cruiser is no exception. In fact, Sol Cruiser has impeccable GDW lineage. In addition to the obvious Star Cruiser influence (emphasis on detection and long-range missile fire), the movement system is a modified version of GDW's old "Triplanetary" game and the stats for TNP drives come from GDW's "Fire, Fusion and Steel".

Speaking of TNP drives, the reason why Sol Cruiser does away with stutterwarp altogether is because it simply does not "feel" right in a near-future SF game. Stutterwarps and other "soft science" solutions, in my humble opinion, are better suited for "far future" games like Traveller, together with grav tanks and power armor. What I like to see in "near future" games is reaction drives, with ships pulling Gs and huge exhaust plumes. I'd bet I am not the only one who thinks in those terms. Heck, even the spacecraft illustrations in some GDW 2300AD books make it look like as if the ships are using reaction drives. Designer's Notes in Star Cruiser actually make a point of how all of the technologies used therein are little more than extrapolations of already existing ones–with the exception of stutterwarp. In my view, it was an unnecessary concession, especially since GDW's own FF&S already contained a feasible alternative to stutterwarp in the form of the TNP drive. It would have been better off to confine exotic technologies to problems truly unsolvable by extrapolating existing or projected technologies. Which is why Sol Cruiser limits "weird science" to FTL travel. Granted, Sol Cruiser sensors seem a little exotic, but I view them as combined arrays of sensors tracking gravity wave disruptions caused by moving objects and the EM signature of TNP drives. They work roughly in the same fashion as Magnetic Anomaly Detectors, except that their sensitivity is vastly greater, as is the signal processing capability. Of course, the notion of detecting a vessel at a range of 1-2 Astronomic Units may sound fantastic, but I think it's justifiable on two grounds: for one, a hundred years ago the notion of a submerged submarine detecting another at ranges of tens of miles through sound waves probably would have sounded pretty fantastic too (not even Jules Verne ventured to make that prediction) and, secondly, unless detection at ranges specified in this game, space combat in the interplanetary space will be a very rare thing. Sol Cruiser vessels are also assumed to possess short-range target acquisition sensors of more conventional types, which they use once they are in the same hex as the intended target. They are not installed separately but instead are "factored into" other ship components, and their effectiveness is simulated by ECM to-hit modifiers.

Regarding the game itself, desirable tactics should become clear after a few games. The basic hints are as follows: high speed means greater signature. If you want to stay unnoticed, go slow. Not being detected means not being attacked, and in addition gives the ship considerable degree of initiative since undetected ships plot their moves after detected ones. Beam battery-armed ships should, when attacking, attempt to minimize Closing Speed, since the slower the ships close with each other, the longer they remain within range of each other's weaponry. However, detonation warhead-equipped vessels (missiles and submunition-carrying ships) should attempt to maximize Closing Speed and thus minimize exposure to point defenses. This means that missiles should be launched as far from the target ship as possible to give them more time to accelerate. At high enough CS's, missiles become virtually unengageable by beam batteries, though they are still vulnerable to submunitions used in point defense role.

More ships designs and rules will follow, as will ship counters and more ship status displays.

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