The Pentagon War game

by Roger M. Wilcox
Originally begun on 27-December-1983

This webpage was last modified on 9-April-2002


ADVANCED RULES

CRASH ACCELERATON

A standard rate of acceleration (three hexes per turn per turn) represents a force of over a hundred gravities.  It is only through tough structural engineering that unmanned fighters may operate under these conditions.  There are times, though, when a spacecraft may need to exceed even this great a force.  Doing this is called "crash acceleration" because several spacecraft systems cannot operate under these conditions and actual structural damage may result.

A spacecraft may crash-accelerate by up to twice a standard acceleration during any impulse.  Doing so requires that extra engines be available for thrust.  A size class II spacecraft wishing to accelerate by one-and-one-half times standard must have three engines available for thrust; a size class III spacecraft wishing to accelerate by twice standard must have six engines so available.  On the acceleration segment of the impulse, the spacecraft's owner declares that it is crash accelerating and writes down how much on his or her acceleration record.  If a spacecraft had facing B and accelerated by one-and-two-thirds times standard on impulse 12, its owner would write down "5/3A+C+" or "1 2/3 A+C+" on the acceleration record's "Impulse 12" line.

For the remainder of the impulse, the spacecraft may not use magnetic beams, ECM, or evasive maneuvering, or fire its weapons at more than one target.  At the end of the impulse, roll two six-sided dice, and if their sum is 12 ("box cars") then structural damage has occurred — roll a single 6-sided die and allocate that many damage points directly to the spacecraft as interior hits.  Regardless of damage, the spacecraft may not rotate by more than 60° (one hex side) on the next impulse.  These restrictions are in keeping with some of the effects of being without control systems, so spacecraft who have lost their main ctrl and aux ctrl may crash accelerate without incurring any additional penalties save for the possibility of damaging themselves.

Manned spacecraft may use crash acceleration, too, when they wish to exceed their normal acceleration of 1/10 hex per turn per turn.  Doing so changes the appropriate velocity component for the spacecraft by 1/60 or 2/120 per impulse.  All the above conditions and restrictions apply, except that the spacecraft will not take any structural damage.

Accelerating by more than twice standard is never allowed.

ELECTRONIC WARFARE

Once you get two sides into a war in which electronic measures are used to locate and lock-on to the enemy, it won't be long before one side develops electronic countermeasures (ECM) to jam the enemy's radar signals.  And it won't be long after that before the other side develops electronic counter-countermeasures (ECCM) to decipher and cut through this jamming.  The result is a lot of time and effort spent by both sides on a game of blinding the enemy while avoiding being blinded themselves.

Every turn, a spacecraft may allocate to ECM and to ECCM a number of power units up to and including its current radar rating.  In multi-spacecraft scenarios, the ECM and ECCM ratings of each side should be averaged from the ratings of all friendly spacecraft.

At the beginning of each turn during the radar lock-on phase, each side announces its ECM strength and ECCM strength.  If the ECCM rating of one side is greater than or equal to the ECM rating of the other side, no adjustments are made.  If the ECCM rating of one side is less than the ECM rating of the other, the radar track of all ECMmed spacecraft is reduced to the next lower box (as though it had taken a radar hit) for every point its ECCM rating is below the enemy's ECM rating.

When using this rule, spacecraft may be bought with special electronics.  This costs 20 points, but these electronics allow a spacecraft to project an ECM and/or ECCM field up to and including twice its current radar rating.  For game balance, if nothing else, these super-ECM/ECCM spacecraft should only be used in fleets of normal-strength ECM/ECCM spacecraft.  Of course, in this case the opposing player need not know which spacecraft in the fleet has the special electronics. . . .

EVASIVE MANEUVERING

When your spacecraft is outnumbered and outgunned, you will generally disengage.  Getting to the point where your spacecraft can disengage, though, can be a harrowing (if not fatal) experience. For this reason, a spacecraft can opt to make small, random changes in its course which do nothing to influence its map movement, but make it a much more difficult target to hit.  It must be noted at the beginning of the turn if a spacecraft will use evasive maneuvering by following one or both of the "velocity component" entries on that spacecraft's Acceleration Record with a /EM.

When a spacecraft is using evasive maneuvering, restrictions (1) and (2) of being without control systems apply to it.  All die rolls for direct-fire weapons fired at or by the evading spacecraft have 3 subtracted from them (2 boxes subtracted from point defense).  Seeking weapons fired by the evading spacecraft have a 1 in 6 chance of not acquiring their target when launched, while seeking weapons targeted on the evading spacecraft have a 1 in 6 chance of missing when they enter its hex (missed missiles may still detonate, though).

Evasive maneuvering requires one engine box in addition to any engine boxes used for acceleration.

SELF-DESTRUCTION

Like ramming, this is not a recommended practice.

On any impulse the player wishes to do this, he or she simply declares, during the Self-Destruction segment, that the unit is self-destructing.  The spacecraft is then removed from the map and explodes.  The force of the explosion is calculated from the following undestroyed systems:

  1. Double the number of undestroyed engine boxes.
  2. Add the number of filled fuel tank boxes, charged capacitor boxes, and undestroyed magnetic beam boxes, screen boxes, and gun boxes.
  3. Add half the number of undestroyed secondary weapons boxes.

This is the basic explosion strength.  As stated in the "Explosions" rules above, it is at full strength in the hex of the exploding spacecraft but loses eight (8) points of strength for every hex distant until it is less than or equal to zero (0).

Spacecraft that are destroyed also explode like this, during the damage assesment segment of the impulse (or whenever the spacecraft is destroyed), but since the damage is calculated from undestroyed boxes, the explosion won't be very strong.

Certain Sirian craft were fitted with "suicide bombs."  These were antimatter warheads tied in with the engines so that they would go off when the spacecraft self-destructed or was destroyed.  They add ten damage points to the basic explosion strength.  Players who wish to fit their spacecraft with these devices must pay an extra ten (10) points for them.  No spacecraft may have more than one built-in suicide bomb on board.

SPEED LIMITATIONS

It is a well-known fact that the interplanetary medium is not a vacuum.  When travelling at speeds of several Mils (Milli-c's, or thousandths of the speed of light) as in this game, every little hydrogen atom in space becomes a cosmic ray, effectively an atomic bullet.  It was for this reason, not combat, that the Alpha-Centaurians developed screens in the first place.

Under this rule, any spacecraft (not size class 0 object) travelling with any velocity component greater than six (6) will take one point of external damage at the end of the turn, after all movement and combat has been completed.  Since screens may negate this, it is unimportant unless a spacecraft's screens are down.

Spacecraft whose screens are down may not disengage by acceleration when using this rule.

RANGED POINT DEFENSE

Normally, point defense may only be used against targets in the same hex as the owning spacecraft.  This optional rule allows P.D. to strike at targets which are further away.

The Universal Range Modifier chart is used to decrease the point defense ROLL (not the number of boxes) for each ranged attack.  Since P.D. is based on a roll of a single die, the Universal Range Modifier will incur a much greater probability handicap to point defense rolls than it does to attack rolls for other direct-fire weapons.  A successful hit indicates one (1) point of damage scored against the target.

As always, point defense may never be fired against the same target more than once per impulse.

Since this rule allows many more opportunities for Point Defense to shoot down incoming missiles — while incurring NO damage to the target spacecraft since they can be destroyed outside its hex — the players may wish to limit ranged point defense to apply to size class I or larger objects only.

SOLAR SYSTEM DIRECTIONAL SCREENS

The Solar System experimental fighter "Zelta Bee" was the first to use this device, although "Zelta Cee" was the first to give it the characteristic pivot (Zelta Bee's directional screen only faced forward) and "Zelta Dee" was the first to give it computer control.

Spacecraft which use directional screens may not use normal screens at all.  The presence of directional screens on a spacecraft, therefore, increases the cost of its screens to 33 points per box.  The directional screen is a system whereby the screens are not distributed evenly over the spacecraft but are focused into a tight, spotlight-like beam that can be aimed in various directions.

The capacitor power cost to operate directional screens (including both reinforcing them and running them at normal strength in a low Alert Status situation) are the same as they are for normal screens.  Each impulse, a directional screen may be aimed in one direction — along the path of one spacecraft, against incoming seeking weapons from one side, etc.  It may count against all direct-fire weapons from one spacecraft, but not against another spacecraft unless the two firing spacecraft are colinear with the defender.  This "colinearity" is determined by drawing an imaginary line from the target to the farthest spacecraft.  If this line passes through the hex of the other firing spacecraft, they are colinear and may both be deflected by the directional screen.

Normal screens are subtracted from the total damage received in a single impulse.  Directional screens, on the other hand, are subtracted from the damage of each individual weapon they are counted against.  Thus, a spacecraft with 8 directional screens may be damaged by a not-stopped missile but may not be damaged by any number of electron cannons fired at it from a single spacecraft.

HYPER BOMBS

These are the devices that originally blew open the hyper holes between the star systems.  They are very large antimatter warheads that emit their outputs "in phase" (as does a laser) and thus can exceed the energy density limits of real space.  When positioned at both endpoints of an intended travel route, aimed at each other, and detonated simultaneously, they create a hyperspace short-cut between the two points.  When detonated by themselves, the effects can be devastating.

Hyper bombs are (very) occasionally mounted atop the rocket vehicles used for ordinaly missiles.  Thus, in play, they can operate exactly like normal missiles except that they do not detonate when destroyed (their power is far too great to risk destruction trip-switches) but are removed from play (until later recovered).

A hyper bomb does not have to be targeted on anything specifically, but its launching spacecraft must be within 30 hexes to guide it.  When the warhead is detonated, which must be done while the missile is not yet destroyed, everything in its hex is destroyed so fast that they don't even get destruction explosions, including planets!  Furthermore, it goes off with (effectively) a basic explosion strength of 32, so everything one hex away takes 24 damage points, two hexes away takes 16, three hexes away takes 8, and four or more hexes away is unaffected.

Hyper bombs will usually not be available unless specified by the scenario.  They may be purchased for 50000 points apiece, though.

MOVABLE BASES

Normally, those craft without engines are considered to be very huge or anchored to asteroids or whatnot so that magnetic beams will not affect them.  However, a base may be declared to be movable.  If this is the case, friendly spacecraft may tow it with magnetic beams just as they would any other spacecraft.  Further, if being towed by a radar invisible spacecraft and radar invisible itself, a movable base can give itself away and re-establish radar invisibility.  Note, however, that enemy units can magnetic-beam movable bases as well as can friendly units.

REPAIRING DAMAGE

No spacecraft may repair itself in combat.  However, in between scenarios of a campaign game, all manned spacecraft and bases that have Repair boxes, and all unmanned spacecraft joined to these spacecraft and bases, have a limited ability to repair themselves:

  1. All hits on Repair boxes are erased.
  2. All Hull hits (Forward and Aft) are erased.
  3. Count the number of Repair boxes on board.  This is the total number of control systems (Main Ctrl or Aux Ctrl) that may be repaired.
  4. Multiply the number of repair boxes by 2.  This is the total number of capacitor or engine boxes that may be repaired.
  5. Multiply the number of repair boxes by 2.  This is the number of weapons boxes that may be repaired.
  6. Multiply the number of repair boxes by 3.  This is the number of non-weapons, non-engine, non-capacitor, non-control boxes that may be repaired.

Although cargo, drone, missile, and fuel boxes may be repaired, they will be empty.  Mark repaired bays with a dot to indicate that they are empty.  Drone and missile bays thus repaired may be subsequently reloaded from cargo storage (but then the cargo bays so depleted have to be marked with a dot).

Repair boxes cost three (3) points each.  NOTE: Although an unmanned spacecraft may have repair systems, they are non-functional unless the spacecraft is joined to a manned one.

PLANETS AND ASTEROIDS

Large terrestrial planets such Earth, Venus, and Mars completely fill not only their counter's hex but several hexes surrounding it.  The Earth and Venus, for instance, are considered 5 hexes in diameter and therefore extend for two hexes in all directions beyond their counter.  (Mars is only three hexes in diameter and thus extends for one hex beyond its counter in all directions, filling the six surrounding hexes.)  Any spacecraft forced into a hex that the planet occupies is assumed to ram it (q.v.).

Weapons directed at such a planet actually strike the surrounding hexes rather than the central hex with the counter in it, and ranges should be measured accordingly.  However, if the planet has an atmosphere, all direct-fire weapons fired at the planet do one (1) less damage point than they would normally.  This reflects the interference a thin atmosphere gives to weapons.

Smaller planets, such as Mercury, Titan, or Earth's moon, fill only the hex their counter occupies.  Any spacecraft forced into the hex of a planet is assumed to ram it, just as for larger planets.  Objects in orbit around these planets travel in a hexagonal path of any radius out to five hexes.  They orbit at a speed of one hex every ten (10) turns.  A spacecraft must be travelling at speed 0 or 1, in the proper direction, before it may declare itself to be "in orbit."  Maintaining orbits requires no engines.

Spacecraft and bases may elect to "hide behind" large planets.  If a planet hex is along the line of fire between two spacecraft, a radar lock-on may not exist between the spacecraft, and they may not fire direct-fire weapons at each other.

Really small moons and large asteroids, such as Jupiter's Amalthea or the asteroid Ceres, do not fill an entire hex.  These are typically used as "anchors" for bases, so that the base may not be drawn by a magnetic beam.  Planets, moons, and large asteroids, like non-movable bases, are assumed to have infinite mass for magnetic beam purposes.  However, small moons may be in orbit around larger planets.

Bolt-style direct-fire weapons (proton cannons, electron cannons, and acid gum guns) fired as "planetary bombardment" automatically strike their target, all the way out to their maximum range.  Only if the weapons are directed at a smaller "ground installation" must hits be determined by dice roll.

Gas giants are super-large planets like Jupiter, Saturn, Uranus, or Neptune.  They have diameters so large that their edges may simply be declared as one of the edges of the playing map.  Even though they are essentially "all atmosphere," no weapons may be fired through them.  Missiles and drones within a gas giant's perimeter will be instantly vaporized due to air friction.  Liquid metal gun bolts will be stripped of their magnetic bottle and disperse.  Any spacecraft going through a gas giant will take the its absolute speed (q.v.) in damage points each and every impulse it is inside the planet.

ALERT STATUS

A spacecraft's Alert Status (AS) affects what systems are available on the very first turn of combat.  The turn after initial detection, all systems (except for multi-turn-arming weapons) are available at full power; but during that first turn, the unit will be less operational, as follows:

Normally, a spacecraft will be fully aware of the presence of the enemy and will have its proton and electron cannons warmed up and its guns charging (or being held) far in advance of the battle.  It is only because of radar invisibility and emergence from hyper holes that spacecraft will not be on alert and warming-up rules are given.

MOVING WITH A FRACTIONAL VELOCITY COMPONENT (OPTIONAL)

An alternative, albeit more complicated, method than the "round down" rule is to have a spacecraft that has a fractional velocity component move faster on some turns but not all of them.  If your spacecraft's A-component was -3 and 1/2, for instance, it would move three times in direction D on all odd-numbered turns (just like before) and four times in direction D on all even-numbered turns.  If its A-component was 5 3/4, it would move six times in direction A during turns 2, 3, 4, 6, 7, 8, 10, 11, 12, etc. — i.e. it would get an extra move on all turns which are not one more than a number divisible by four.  If its A-component was -1/4, it would move once in direction D on only those turns that were divisible by four (4, 8, 12, etc.).

This also works with spacecraft travelling with fractional components that aren't increments of one-fourth.  Say you have a spacecraft with a C-component of 1 and 5/27, and you wanted it to move faster some of the time.  In that case, you would group the turns together into clumps the size of the fraction's denominator (27) and apportion a number of them equal to the numerator (5 of them), as equally spaced as possible and with the final (27th) turn always getting first dibs, to be turns when the spacecraft moves faster.

This is most useful for slow-moving spacecraft, such as manned vessels or spacecraft orbiting planets, so that they will get to move a little bit even though both of their velocity components have absolute values smaller than 1.

CHANGING VELOCITY IN MID-TURN

When accelerating by fractional amounts during several impulses, you may find one (or both) of your velocity components going just high enough to count as one higher on the current turn.  Or, you may find one or both components going just low enough to count as one lower.  In these cases, the component(s) will change on some impulse in the middle of the turn, when you apply that last fractional bit of acceleration.

Immediately on the impulse this happens — even before the movement segment starts — the spacecraft will use the next higher (or lower) column on the impulse chart for the affected component(s).  That is, if the spacecraft has an A-component that counts as 4, and on impulse 6 it finishes accelerating its A-component to 5, it will switch to the "5" column on the impulse chart, where on impulse 8 a move (move number 3) is indicated.

There are two instances that must be handled specially:

  1. The spacecraft finishes accelerating a component to an absolute value 1 greater than it was previously, but it does so on an impulse where its old component had a move indicated and its new component does not.  In that case, it will have "missed its move" if it follows the new column as shown.  If this happens, the spacecraft does get to move this impulse even though its new speed doesn't have a move indicated.
  2. The spacecraft finishes decelerating a component to an absolute value 1 less than it was previously, but it does so on an impulse where its old velocity does not have a move indicated while its new one does.  In that case, it does not get to move, even though the new column says it should.

Thus, a spacecraft that accelerates its A-component from -5 3/4 to -6 on impulse 3 gets to perform its "move number 1" on that impulse, since move number one in the "5" column does indeed happen on impulse 3 but move number 1 in the "6" column was already supposed to have happened back on impulse 2.  A spacecraft accelerating its C-component from 9 to 10 on impulse 11, however, does not get to make two moves in direction C that impulse just because it "would otherwise have missed move number 8" — missed or excess move numbers only apply on impulses where one column has a move indicated and the other does not.

The same two "special" instances described above can also happen if you are playing with the "moving at fractional velocities" rule.  On turns where an acceleration "skips" a listed number (and therefore forces the spacecraft to move at the lower speed when it would otherwise have moved at the higher one), the spacecraft gets to move with the higher speed.  The reverse is true for decelerations on turns which "repeat" a number already used.

ACTION-REACTION WITH MAGNETIC BEAMS

A spacecraft with a magnetic beam attached to another spacecraft does not get to magically "pull" the other spacecraft through space without being pulled itself.  The attraction or repulsion is mutual.  Every "Engine" worth of force that a magnetic beam exerts on its target is also exerted on the spacecraft using the magnetic beam.

To reflect this, every impulse that a magnetic-beamed spacecraft is accelerated in a particular direction, the magnetic-beaming spacecraft is also accelerated in the opposite direction.  For instance, a spacecraft using a magnetic beam to repel another spacecraft directly above it on the map would accelerate that spacecraft in direction A, forcing its owning player to write down an "A+" on its acceleration record for that impulse.  However, the spacecraft using the beam would also accelerate itself in direction D, and the owning player must write down an "A-" on the same impulse of that spacecraft's acceleration record.

With spacecraft of different sizes, things get even more interesting.  Recall that it requires the thrust of 2 engine boxes to accelerate a size class II spacecraft at the standard rate of three hexes per turn per turn, or 1/4 hex per turn per impulse.  However, this same amount of thrust applied to a size class III spacecraft would only accelerate it at a rate of two-thirds standard, or 1/6 hex per turn per impulse (its owner would write down "2/3A+" or "2/3A-C-" or whatever on its acceleration record).  Furthermore, this same amount of force would accelerate a little size class I spacecraft at twice the standard rate, bringing it into the realm of Crash Acceleration!  The rule here is that as many units of engine thrust are applied to the beamer as the beamer applies to the beamee.  If this produces a higher acceleration than standard, the spacecraft is considered to be crash accelerating that impulse, with all the inherent restrictions that such an action carries with it.  If this produces an acceleration higher than twice standard, the spacecraft may not even perform such an operation.  Thus, no magnetic beam or combination of magnetic beams is ever allowed to generate more engines worth of thrust than twice its owner's size class.

Since bases are assumed to have infinite mass with respect to magnetic beams, they have a tremendous advantage in that they can tug on other spacecraft all day without dislodging themselves in the slightest.

MASS AS DISTINCT FROM SIZE

Although a spacecraft's size class is a pretty good approximation of its mass, it does tend to fall short.  It does not, for instance, take into account the fact that one box worth of armor weighs a lot more than a box worth of hull or cargo hold.  It also does not account for little pieces of the spacecraft getting "blown away" in combat.

For a better approximation to mass, total the following:

  1. Sixty times the number of undestroyed ramming weight boxes
  2. Thirty times the number of destroyed ramming weight boxes
  3. Four times the number of undestroyed armor boxes
  4. Twice the number of destroyed armor boxes
  5. Twice the number of undestroyed non-ramming-weight, non-armor, and non-radar boxes
  6. The number of destroyed non-ramming-weight, non-armor, non-radar boxes

This is the number of "mass points" the spacecraft weighs.  Divide this by 300 to arrive at the mass class of the spacecraft.  You may either make your life simpler by rounding this mass class up to the nearest higher whole number, or make things more interesting by playing with a fractional mass class.  This mass class is used instead of the size class when determining engine requirements, magnetic beam effects, and ramming damage.

Since calculating the mass class of a spacecraft on the fly is quite time consuming, it is recommended that the undamaged mass of each spacecraft be calculated in terms of mass points before the scenario begins; then this mass point rating can be easily reduced by 2 for each armor hit and 1 for each non-armor, non-radar hit taken during the course of the scenario.

TRIGONOMETRIC FORMULA FOR ABSOLUTE SPEED

The simple biggest-or-sum formula given in the movement rules for determining speed is not entirely accurate.  The speed of a spacecraft is actually the vector sum of its two velocity component vectors.  Since the A and C directions are 120° apart, rather than 90° apart, some terms have to be introduced into the formula to take this extra 30° into account.  If the players are up to using a calculator, the actual formula to find the speed S, given velocity component values A and C, is:

S = √ A2 + C2 – A . C

. . . or, in English, the speed is the square root of: the square of the A component value, plus the square of the C component value, minus the product of both component values.


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