Optional Rules: Misc.

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.

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Dropships | Warships
VehiMechs | Centaurs | Spiders

Misc

Lifting

see Physical Combat

Buried Mechs (sand)

(obsolete)
Buried mechs are considered hidden. Like all hidden mechs, it is no longer considered hidden on the turn it moves. It costs 2 MP and 2 generates Heat Points to unearth a mech, including the cost of standing. No piloting skill roll is required. The mech can assume any facing the player desires. Movement is initiated at the begining of the mech's movement phase.

Mechs cannot fire while buried.

OPTION: Surfacing mechs may not move on the turn they surface, but they may fire normally.

This rule is based on The Fox's Teeth: Exploits of McKinnon's Raiders, a BattleTech supplement (1606) published in 1986 and The Spider and the Wolf. FLUFF: McKinnon's Raiders' scenarios take place in 3029. Black Widow Company's scenarios take place 3014, around the time of the death of Joshua Wolf, Jamie Wolf's brother and Natasha Kerensky's lover.

Cold Weapons

see Heat Build Up

Critical Hit-Sensors

A critical hit to the sensors normally blinds a 'mech. A 'mech with a C3 computer (slave or master) is immune to this effect until both the sensors and computer are destroyed. The 'mech relies on the sensors of its lancemates. Other 'mechs on the circuit can not use the damaged 'mech for targeting as per normal C3 rules.

OPTION: Damage to sensors may also result in damage to the read-outs and displays in the cockpit. The 'mech may continue actions at a +1 penalty to Piloting and Targeting.

OPTION: Blocked LOS to C3-equipped lancemates (with functioning C3 equipment) renders the 'mech blind until LOS is restored. This can be firing LOS or only LOS blocked by buildings and hills (valleys) to reflect scanner ability to penetrate wooded hexes.

Engine-Offset

The engine of a BattleMech may be placed in an alternate Torso location. The gyro, however, must be placed in the opposite torso to maintain balance.

Engine-Twin

A BattleMech may use two engines to supply power. This can result in an engine rating higher than the previous limit of 400. Both engines must be of the same type and cannot be XL-type engines (or Level III engines other than Compact). The engines must be placed in the left and right torsos; the gyro remains central. Control and interlink equipment must be added to synchronize the engines: this equipment takes up 1 critical space and 5 tons per 100 points of Engine Rating (round up). Dual engines only have space for 1 Heat Sink per 50 rating points instead of the usual 25. One engine must be designated as the primary engine in case of damage to the secondary engine or interlink equipment. If the primary engine is damaged, there is a 4-in-6 chance that the secondary engine will still operate. Destruction of the interlink equipment prevents the secondary engine from functioning. Heat-related penalties still affect 'mech movement. Engine Damage-related penalties to movement are halved. Each engine has 3 damage points.

Twin-engine 'mechs running on one engine generate an additional 4 points of heat and only use the Power Rating of the working engine. Recharge times for energy weapons and gauss rifles are doubled. If you do not use recharge times, small and medium lasers may be fired every other round; LLs, PPCs, and GRs may be fired every third. ECM and Active Probes are automatically swithced off to conserve power.

ESR

(obsolete/adaptation)
The maximum range of a Battlemech's Electronic Sensing Radar is 30 hexes (900m), just shy of 2 mapsheets (34 hexes/1020m). ESR requires Line of Sight to function. The ESR can only identify the type of ground unit occupying a hex, e.g. 'mech, vehicle, infantry, etc.. Air units are automatically identified (at least by class) within 100 hexes/3km (actually, 102 hexes) and not affected by LOS except for Heavy Woods and Buildings.

Actual 'mech sighting is limited to a mere 6 hexes (180m), regardless of LOS. Enemy 'mechs can still be targetted outside this distance; they simply cannot be identified. Your GM may wish to increase this limit to a more practical 10 hexes or even 17 (1 mapsheet).

'Mechs using Active Electronic Probes (AEP) can determine a target's class and capabilities (including a rough estimate of damage) of any units within ESR range. At the GM's option, an AEP will provide the experience level (green, veteran, elite, etc.). To rationalize experience being known, assume that a specific 'mech can be tracked by its markings and a database provides the last known pilot.

Recon battlemechs may be outfitted with an advanced version of ESR. The recon ESR extends range an additional 360m, to a total of 1260m (42 hexes).

This rule is based on BattleForce, a sequel to BattleTech published by FASA in 1987. BattleForce was a game of "small unit actions" that used lance-sized units instead of individual battlemechs. BattleForce was written based on Level I rules.

Foxholes

(oblsete)
Foxholes (presumably excavated before a scenario) may be used to protect defending mechs. A foxhole surrounds the mech entirely and provides partial cover as a level 1 elevation.

This rule is based on The Fox's Teeth: Exploits of McKinnon's Raiders, a BattleTech supplement (1606) published in 1986.

Head-Offset

Many 'mech designs show 'mechs with offset heads. These heads appear to be mounted on or in the side torsos of their 'mechs. To simulate a practical use for these designs confer a -1 bonus to arm-mounted weapons on the side with the head and a +1 penalty to weapons on the arm opposite the head. These modifiers reflect the changed perspective. Maximum Tech, FASA's rules expansion, mentions this, but provides no rules for this design.
NOTE: Destruction of the corresponding torso location also destroys the BattleMech, as the head no longer has support.
NOTE: Pilots using this design for the first time suffer a +1 Piloting penalty. Pilots returning to normal 'mechs suffer a +1 Piloting AND Targeting penalty on their first sortie.

An offset head may also be recessed.

An offset head may also be fully recessed into the torso (ala Thunderbolt). The head cannot be targeted from the rear; hits to the head must re-roll for a new location. A fully recessed head still weighs 3 tons and takes up four critical spaces: 1 Cockpit, 1 Life Support, 2 Sensors. The head adds 2 Internal Structure points to that torso location.
OPTION: A "headless" BattleMach may mount up to a 3-Critical Space weapon in place of the head. The weapon may have up to 3 points of armour per critical space. Such weapons are targeted as a head. Additional damage transfers to Center Torso except on Critical Hit--Head Blown Off.

Head-Recessed

NOTE: This design is different from the rules listed in Maximum Tech for Torso Mounted Cockpits.
Certain BattleMechs are shown with heads that could not be possibly targeted from the rear. These 'mechs include the Timber Wolf (MadCat), Catapult, Marauder, Stalker, and Bushwhacker, among others. While the aesthetic value of such depictions is appreciated, the practical value should also be available. Imagine the comfort of being tucked behind your BattleMech's primary armour. Watch your opponents surprise as your 'mech fights on... after its head is blown off!
NOTE: This ruling is not an automatic retrofit for the above-mentioned 'mechs; Battlemechs like the Catapult already have equipment in their center torso locations.

The recessed head unit still weighs 3 tons, but only has 4 critical spaces (re-roll for missing critical hits). Recessed heads cannot mount weapons and can only carry 6 points of armour instead of 9. The Cockpit and one of the Life Support critical hits are re-located to the center torso. For ease of use with standard record sheets, fill in the usual slots in the Center Torso; the cockpit is not considered to be below the engine, much like arm-mounted weapons are not considered to be below the hand. Destruction of the traditional head area now transfers damage to the Center Torso. A Critical Hit resulting in Head Blown Off does not transfer excess damage to the Center Torso. NOTE: Although the Center Torso offers more armour protection from the front, it is relatively vulnerable from the rear. The Center Torso is slso more likely to take damage than the head. The mechwarrior is also more likely to be killed in an ammo explosion in 'mechs without CASE.

Heat Build Up

Weapons fire is the primary reason most 'mechs overheat. Heat build up and heat dissipation rates are based on constant use. Cold weapons should not add as much heat as recently fired weapons. Any weapon (except the machine gun, obviously) that has not fired in as many turns as its Heat rating causes one less point of heat than normal. Small Autocannon might not generate heat at all if fired on alternating turns.

Note: This rule can lead to devastating first-round exchanges especially from long-ranged assault 'mechs.

Hot-Loading

Reinforced Cockpit

Jump Jet Attack

(clarification)
The Level III Jump Jet Attack allows BattleMechs to fire any weapons (other than those on the legs). Prone 'mechs cannot fire normal weapons unless they prop themselves on one arm. Also, see the revision to Prone 'Mech facings below.

Prone 'Mechs

Prone battlemechs may prop themselves up on one arm to fire weapons.
Front-Facing: only the free-arm and the head should be able to track targets.
Side-Facing: if the 'mech props itself and rolls to the side, it can bring all weapons (including leg-weapons but not weapons on the supporting arm) to bear. Attacks to this "side" can cause the 'mech to roll onto its back, requiring an additional turn to right itself. Require a piloting skill roll for damage above 15pts. taken in one turn. Assign a +2 (penalty) modifier to a piloting skill roll for successful physical attacks from that side.

Reversed Arms

The rules state that a 'mech missing hand and lower arm actuators on "either" arm, may swing up and reverse their arms in place of a torso twist. The ruling states that both arms must swing around simultaneously (barring loss of an arm, assumed), but does not state that both arms be without hand and lower arm actuators. Without such clarification, it could be inferred that it is allowable to swing back only one arm (sans actuators). It is up to the Game Master (or mutual player consent) to require both arms to be without hand and lower arm actuators. This rule implies a different shoulder configuration for 'mechs designed without hand and lower arm actuators.

Reversed Knees

BattleMechs may be designed with "reversed knees" like those shown on the Catapult and Marauder. Reversed Knees are considerably more stable than human-like knees. GMs may wish to allow -1 (bonus) to piloting skill rolls for 'mechs with reversed knees. Reversed knees make uphill travel easier, giving +1MP (bonus) to forward uphill travel. Going downhill or in reverse is more difficult for BatleMechs with Reversed Knees. Inflict a -1MP penalty to downhill or reverse movement and remove the piloting skill bonus. 'Mechs going backwards and downhill recieve a -2MP penalty, possibly making such movement impossible, if backwards elevation changes are allowed in your campaign.

Reversed Knees also allow a 'mech to "hunker down" or go "hull-down" (pg 20, Maximum Tech) like a quad. A 'mech that "hunkers down" can take advantage of partial cover and elevation dead zones.

Turret Mounted Weapons

Current rules assume that all turreted weapons face in one direction. Turrets, like 'mechs, can have rear-mounted weapons. Rear-mounted turret weapons, denoted by the standard (R), use a rear firing arc based on the facing of the main turreted weapons. This allows the vehicle to attack multiple targets in different arcs. Since BattleTech maps are based on hexes, use of side-mounted turreted weapons unnecessarily complicates the game.

Underwater

(obsolete)
Mechs in Level 2 water are considered under partial cover, except to mechs in adjacent hexes.

Prone mechs in Level 2 water are considered hidden, even after firing, except to mechs in adjacent hexes.

Underweight 'Mechs

A battlemech may be underweight. Your GM should rule whether the limit should be .5 to 4 tons. 'Mechs are only underweight when they have maxed out their critical spaces and armour. A piloting penalty may apply, usually after a physical attack, but is usually ignored. Physical attacks may also be penalized, the 'mech attacking as one 5 tons lighter. Sand (or equivalent) may be used to round out the 'mechs weight.

This is about the same as allowing BattleMechs to carry cargo space.

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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