Optional Rules Compendium

This is a compilation of "house rules" for the BattleTech gaming system. These rules come from different sources and might not be used by your GM. If your gaming group does not use a GM, then rules can be adopted by general consensus of the players. Please note that some of these rules may conflict with each other; this list is meant to complement existing rules.  This list is based on FASA's BattleTech, not the newer version by FanPro (Classic BattleTech).
Use of the phrase "House Rules" in no way implies that the sequenced garbage played in dance clubs in the early 1990's was even music, let alone any good.

Actuators* Armour* Critical Spaces* Conventional Aircraft* Damage and Repair* Endo Steel* Ferro Fibrous* Hatchets* Heat Sinks* Misc.* Physical Combat* ProtoMechs* Quads* Weapons and Equipment
Dropships | Warships
VehiMechs | Centaurs | Spiders

Weapons

Adjacent Ammo

Ammuntion for weapons must reside in the same or an immediately adjacent location. Machine guns can be an exception to this rule.

Artemis III

Artemis IV

All missile launchers of the same type (SRM/LRM) do not need to be Artemis equipped.

A single Artemis IV system can guide all launchers in a single location (even if different types).

Every single launcher must have a Artemis IV designator mounted to it to benefit from its use.

An Artemis IV system in the Center Torso may guide a head mounted missile launcher.

A single Artemis IV unit may guide any Artemis-equipped missiles that share its firing arc.
Missiles fired at targets outside of the firing arc, even though Artemis-equipped, do not recieve the Artemis IV bonus.

Hand-held (see Tactical Handbook) Missile Launchers may be used by 'mechs with Artemis systems. Hand-held weapons cannot have Artemis IV, however. This overrides the all launchers of a particular class must be Artemis equipped.

Artemis equipped launchers may be loaded with normal missiles (to save cost). These function as standard missile launchers but still damage as normal Artemis launchers.

Battle Mace

see Hatchets

Carrots

Battlemechs may not use giant mutant carrots for clubbing attacks. Carrots are too fragile to make effective weapons. The do not have enough distraction or impact value to warrant a piloting skill roll. Carrots may not be used to hide 'mech weapons as the extreme heat turns the carrots to mush.

Chaingun

(unofficial)
Battlemechs may mount the same type of chaingun found on conventional aircraft.

It weighs more than a standard machine gun, but has slightly better range.

Based on Top Gun (© 1986 Paramount and FASA) rules. Based on the AeroTech conversion rules.

Conventional Controls

Conventional Missiles

Battlemechs may mount the same type of missiles found on conventional aircraft.

This rule is being revised to compare with Maximum Tech IR-LRM rules.

Based on Top Gun (© 1986 Paramount and FASA) rules. Based on the AeroTech conversion rules.

Deflector Shields

Development

(philosophy)
Among the popular board/role-playing games of the late 80's was a game called "Car Wars". Many people developed their own weapons for both games, however BattleTech rarely adopted new ideas. Like BattleTech, Car Wars weapons were limitted by space and weight, but, MechWarrior was released, Car Wars alone had the limit of cash. Car Wars had a limitaion of accuracy, which until recently, BattleTech never had (although varying ranges were similar); BattleTech does have the aditional limitation of heat.
As with Car Wars, BattleTech weapons can be designed on similar guidelines. The most likely restriction is in C-Bills, as unlimitted class (fund-wise) battles are practical for seasoned players and no fun for beginners. Size already rules out weapons like the Long Tom for BattleMechs.

An example of the development philosphy is seen in the Autocannon family of weapons. BattleTech originally started with 1 type of autocannon, simply called AC not AC/5. At the release of CityTech, that family grew. Now, there are over a dozen cannon to choose from. They are restricted by damage, heat, size, range, cost, weight, and even ammo.
Another example can be seen in short-range weapons. The Flamer does same damage as the Small Laser, but causes considerably more heat than its more expensive counterpart. The Machine Gun is cheaper than the Small Laser, but is restricted by Ammo (although it's hard to use up 200rds. with one MG) and takes up more space and weight when ammunition is figured into the equation.

These guidelines are used to judge new weapons submissions to this archive.

Rough guidlines:
Every 2pts of Damage take about 1 Critical Space.
Every 1pt of Damage weighs about 1 ton.
Every 3 Hexes of Range add 1 ton.
Weapons requiring Ammunition subtract 1 Critical Space (min. 1).
Ammunition does 100pts of Damage per ton, adjusted by range.
Energy weapons generate heat and damge on a point for point basis.

EMP Cannon

EMP Missiles

FSDS Rounds

Gauss Rifle

see also Damage

Grenade Launcher

This type of launcher is different from the kind listed in Maximum Tech.

Hands

Arm-based weapons, such as PPCs are often assumed to warrant the lack of hands on a BattleMech. The BattleTech PPC is actually a compact weapon; although it weighs a hefty 7 tons, it only takes up 3 critical spaces. 'Mechs often depicted without a hand may be considered to have a hand if space permits. This would allow these 'mechs to manipulate objects (clubs) and allow them easier punching attacks. Conversely, 'mechs may have their hands and lower actuators removed to allow for reversed firing arcs. A 'mech cannot take advantage of both these situations.

NOTE: OminMechs cannot have hands on arms mounting PPCs and/or autocannon.

Hatchets

see Hatchets

IFF

IR Laser

Manrikigusari

The manrikigusari, chain flail, was derived from a utility chain designed for utilitymechs. The weapon version has a weighted barb and a rapid deploy and retrieve system. The manrikigusari achieved a high popularity in the Draconis Combine in the late 3050's, with the introduction of 'mech-mounted swords.

To strike with a manrikigusari, a 'mech must make a successful punching attack with the flail-equipped arm. Hit location is rolled on the standard hit location table, not the punching location table. A hit to any location other than the center torso requires the defender to make a piloting skill roll.

* a successful piloting skill roll after a strike to the arm requires the attacker to make a piloting skill roll (at -2 bonus) to prevent being pulled over.

'Mechs attacking form different elevations use the punching/kicking hit location table.
A BattleMech attacking a 'mech at a lower elevation must make a successful piloting skill roll (at -1) after a successful hit.
Successful hits to the center torso only inflict damage and do not allow a grapple.

A 'mech may only make one manrikigusari attack per turn.

The chain is assumed to retract after use, and cannot be targetted or grabbed. A defending 'mech with functioning hand actuators may attempt to grab the chain during an attack. Since all attacks are resolved simultaneously, an attacker must claim to be making a flail attack at the beginning of the attack phase. The defender must them claim to be grabbing the chain, if desired. The actual combat rolls do not need to be resolved immediately. Grabbing a manrikigusari reults in an automatic hit to the defender's arm. Actually grabbing the chain requires a successful punching attack roll. 'Mechs attempting to grab a manrikigusari may not make any other attacks with that arm in the same turn. A BatleMech may attempt to grab with both arms. Only one arm takes damage, regardless of success. Both arms must still be committed to the grab, even if the first succeeds. A successful grab with one hand requires a piloting skill roll for both 'mechs (+1 penalty to the attacker). A successful grab with both hands requires both 'mechs to make a piloting skill roll (-1 defender, +3 attacker).
The GM may also add a 1-point modifier for every full 20tons difference in mass.
A 'mech cannot defend against a manrikigusari attack from a lower elevation.

LEVEL III OPTION:
A manrikigusari may survive a critical hit. The critical hit is assumed to have damage the retractor mechanism. If the 'mech made a manrikigusari attack, the flail is assumed to be locked in the out position. If the 'mech did not make a manrikigusari attack, the weapon is locked in its housed position. Some mechwarriors leave their flails deployed to avoid this and give themselves a psychological edge. Permanently deployed flails may be targetted as per normal called shot rules. A successful hit destroys the flail, but only transfers 50 percent of the damage (round down) to a random location. Switching from a called shot to a normal attack in the same round carries the +1 multiple target penalty.

Microwave Laser

Mine Dropper

Reinforced Fist

see Hatchets

Rockets

Sabot Rounds

Shields (hand-held)

Hand-Held Shields are constructed as normal hand-held weapons (see Tactical Handbook) except that the internal structure (handle, framework, etc.) weighs 1 ton per ton of armour. Each 1 ton of IS is capable of absorbing 1 damage point with excess damage passing on to the 'mech. This prevents BattleMechs from lugging aroung huge 160pt shields.

Mechs without funtioning hands may not carry shields. Mechs armed with hatchets and the like may not use shields, either.

Mechs may not fire arm mounted weapons (on the shield arm) while carrying the shield. Arm-mounted AMS weapons may fire, as they are automatic, but they have a 50% chance of hitting the shield instead of the incoming missiles. Treat this as an attack by an AMS (per Maximum Tech) against the shield. Excess damage not absorbed by the shield may be converted into a normal AMS response to a missile threat, but the shield is still destroyed. Torso mounted AMS units are considered to be mounted high enough to avoid interference from the shield.

To reflect the bulk of the shield you may:

Hits to the centre torso, and front side torso of the side that has the shield arm also must roll and aditional die to see if the hand-held object is hit instead.

Double the chances of the shield being hit instead of the original target location.

Smoke Screens

Split Allocations

(clarification)
Both the 4th ed. Rulebook and the 2nd ed. Compendium state that AC/20 type weapons may have their Critical Spaces split between 2 adjacent locations. This does not include AC/5s and AC/10s; it refers to normal, LB-X and Ultra model AC/20s. This ruling would make more sense if the 4th ed. Rulebook contained LB-X and Ultra autocannons.

Swords

see Hatchets

Tesla Cannon (Lighting Gun)

Tetsubo

see Hatchets

Underwater

see also Misc

Underwater

(obsolete)
Non-energy weapons may be used underwater. This chart may be used, in whole or in part, with current rules.

Missiles and PPCs are not affected. Machine guns and flamers do not function.

From The Fox's Teeth © 1986 FASA. From the "Water, Water Everywhere" campaign scenario

XRMs

To submit a rule for posting, e-mail Koichi (please include "BattleTech" in the subject line)

This list was compiled by Jason Caesar and Koichi Ishitandai

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