OBT Forum

Master Arminas’s BattleTech Rules

Through the many long years of this game that we all know and love, we fans have grumbled, we have cursed, we have wonder why oh why does it depart so radically from the physical laws of the universe as we know it.  Machine-guns with a maximum range of 90 meters; 200mm automatic cannons with a range of 270 meters; ‘missiles’ that are nothing more than unguided rockets—tragically short-ranged unguided rockets.

This is my attempt to correct the shortcomings inherent in our game.  Unless otherwise stated, normal BT rules apply.

Scale

Each hex on a BattleTech mapsheet measures roughly 200-meters in diameter.  Each elevation shown on a map (positive, as in hills, or negative, as in sinkholes and water depth) is roughly 6-meters in height, or approximately waist high on most BattleMechs.  Ground vehicles have their line of sight blocked by Level 1 or higher elevation.  On a terrain board without hexes, one inch (1”) of measured distance is 100-meters.

In BattleTech, each game turn lasts for approximately 1 minute of real-time.

Pilot and Gunnery Skills

People with no training cannot pilot or operate a BattleMechs weapon systems.  Unlike the canon system, in this system, the worst possible starting Pilot/Gunnery skill is 0/0.  Normally, green MechWarriors who have successfully finished training will start the game with skills of 1/1.  Regular troops have an average rating of 2/2.  Veterans tend to have a skill of 3/3, while elite MechWarriors average 5/5.  The highest possible skill in either Pilot or Gunnery is 6.

Anytime in the game that a ‘Mech is required to make a pilot skill check (such as to remain standing), the base To-Hit Number is a 6 (roll 2d6 and beat the target number).  MechWarriors add or subtract any applicable modifiers to this roll, and they subtract their pilot skill as well.

For players in a campaign setting, a MechWarrior may improve their Pilot or their Gunnery Skill by 1 point for every 4 enemy BattleMechs that he successfully kills.  For this purpose, kill means destroying the engine, destroying the gyro, destroying  the cockpit, removing both legs, or eliminating all of the center torso internal structure.  To gain credit for a kill, the MechWarrior in question must have been the only MechWarrior who inflicts internal damage on his target.  Otherwise, the kill is instead recorded as an assist.  If more than four MechWarriors can claim an assist on the same BattleMech, none of them get credit for the kill.  Eight assists equals one kill.

For a random game, use the following to determine starting skill level of the MechWarriors:  roll one (1) d6 for Piloting.  On a result of 1, the MechWarrior is Green and has a skill of 1.  On a result of 2-5, the MechWarrior is Regular and has a skill of 2.  One a result of 6, the MechWarrior is a Veteran and has a skill of 3.  Repeat for the MechWarriors Gunnery skill.  It is not possible for the random system to generate an elite MechWarrior, who are only very rarely encountered on the Battlefield.

Movement

Jump Jets do not generate heat in this version of BattleTech.  However, a fully fueled BattleMech only has enough fuel for 24 jumps (regardless of distance).  MechWarriors must track their jump jet fuel consumption, making off one use for each jump.  When jump jet fuel is depleted, a BattleMech may no longer jump.  Jump-capable BattleMechs may jump up to every other game turn; the jets require one turn to cool between uses.

Combat

Combat is conducted by figuring the distance to the target, the effective range of the weapon systems mounted by your BattleMech, and any pertinent modifiers to the base to-hit number.  It is easier to hit a target a close range than it is to strike a distant target.  Smoke, fog, weather conditions, intervening woods terrain, buildings and other structures:  all of these will modify the listed to-hit numbers.  These numbers are also modified by the type of movement your ‘Mech takes:  whether it stands still (no modifier), walks (+1), runs (+2), or jumps (+3).  In a similar fashion, it is also modified by the targets movement, this time in the total distance movement from its starting point.  This is not the total number of hexes (or inches) moved, but instead the final distance from its starting point to its final location.  This modifier is +1 for the first 3 hexes (6”) of movement in a turn, with an additional +1 for every 2 hexes (4”) thereafter, with an additional +1 being added if the target BattleMech jumped.

The to-hit numbers are not based on the weapon ranges:  in the 31st century only the actual range to the target matters for the fire-control systems on BattleMechs and other combat vehicles.

Up to 200 meters (0-1 hex; 2”):  Base To-Hit is 2.
201-600 meters (2-3 hexes; 6”):  Base To-Hit is 3.
601-1200 meters (4-6 hexes; 12”):  Base To-Hit is 4.
1201-2000 meters (7-10 hexes; 20”):  Base To-Hit is 5.
2001-3000 meters (10-15 hexes; 30”):  Base To-Hit is 6.
3001-4000 meters (16-20 hexes; 40”):  Base To-Hit is 7.
4001-6000 meters (21-30 hexes; 60”):  Base To-Hit is 8.
6001+  meters (31+ hexes; 60”+):  Base To-Hit is 9.

Add to this Modified To-Hit Number, the Pilot skill of your target and subtract your Gunnery skill. 

For example, a Wasp BattleMech is firing on a Stinger at a range of 1800 meters (9 hexes; 18”).  The Wasp ran (+2), and the Stinger jumped 10” (5 hexes) (+3).  Both MechWarriors have piloting and gunnery skills of 2/2.  The Base To-Hit Number for 1201-2000 meters is 5.  Adding the Wasp’s movement makes it an 7.  Adding the Stinger’s movement makes it an 10.  Adding the Stinger piloting skill (2) makes it a 12; subtracting the Wasp’s gunnery skill results in a final modified To-Hit of 10.

Missiles

BattleMechs are often equipped with missiles.  These weapon systems provide a concentrated punch, at the expense of endurance.  Each listed missile rack (SRM or LRM) has a payload:  this is the number of missiles that rack can fire.  MechWarriors can fire a single SRM or LRM in addition to other weapon systems each turn, marking off the used missile from his sheet.  Alternatively, a MechWarrior can flush up to two SRM or LRM racks each turn; the MechWarrior can mix and match SRMs and LRMs, but can only two fire total.  ‘Flushing’ a missile rack immediately launches ALL remaining missiles within the selected rack.  Each missile requires a separate To-Hit roll and deals damage as individual weapons.

In addition to the standard anti-vehicle/anti-‘Mech missiles (known as Hammer munitions), BattleMechs and combat vehicles with missile launchers can carry a variety of other ordnance:  Firecracker missiles are more effective against infantry and soft targets (reverse ‘Mech/vehicle and infantry damage); Inferno missiles are incendiary weapons (SRMs deal 5 points, LRMs deal 3, and engulf the target hex, ‘Mech, or vehicle in flame), and Thunderbolt missiles are anti-bunker weapons (no damage vs. infantry; half damage, round down, versus ‘Mechs and combat vehicles, inflicts twice the listed damage to buildings and structures) are the most common.

LRMs can also carry Illumination missiles (provides 2 minutes of illumination over a 6,000-meter radius) and FASCAM missiles (deposits a single 5-point minefield in the target hex).

LRMs have a minimum range of 2,000 meters (10 hexes; 20") under which they do not arm and inflict one-half normal damage.   There is no To-Hit penalty for firing LRMs under 2,000 meters.  It is possible to hot-load LRMs to arm upon leaving the launch tube; however, if the launcher is hit while the missiles are hot-loaded, all remaining missiles will detonate.

Autocannon

Light, medium, and heavy autocannon may use burst fire.  This expends three units of ammunition and allows the MechWarrior to make two separate To-Hit rolls against his target.  Each successful attack is resolved normally.  Alternatively, the MechWarrior can attack two separate targets provided that they are no more than 200 meters separates the two targets from each other.  All attacks made in burst-fire mode receive a +1 modifier to the To-Hit number, representing the increased recoil.

Anti-Missile Systems

Some BattleMechs are equipped with Anti-Missile Systems.  Only one AMS may be mounted in a single BattleMech.  The AMS may engage up to five missiles in a single game turn; each use expending one unit of ammunition.  Leakers (i.e. missiles engaged but not destroyed) may continue to be engaged, with each successive engagement attempt counting as one use of the system.  AMS will successfully destroy the first missile it engages each turn on a roll of 3+ (this is not modified by gunnery, piloting, movement, or terrain).  Each succeeding missile engaged increases the target number by 2; i.e. the second missile is 5+, the third is 7+, the fourth is 9+, and the fifth is 11+.

MRAS Artillery

A few, rare BattleMechs are armed with MRAS artillery systems.  These systems contain launch tubes for five MRAS Artillery Rockets.  These systems have a minimum range of 6,000 meters and cannot be fired directly; they are indirect support weapons only.  Use standard Arrow IV rules, with the following exception.  Ammunition cannot be added to a MRAS system.  The weight and critical slots is a five box launch cell system; it does not possess an internal reloading system.

ECM

Some BattleMechs are equipped with ECM systems.  These systems jam enemy missiles and provide a +1 to the modified To-Hit number for attacks on this BattleMech with missiles.  If a unit with ECM also mounts an AMS system (see above), his target numbers for engaging incoming missiles is decreased by 1 (i.e., first missile is an auto-kill; second missile 4+, third missile 6+, fourth missile 8+, and fifth missile 10+).

TAG

Some BattleMechs carry a laser-designator for MRAS Artillery and laser-guided bombs deployed by aerospace fighters.

Infantry

Infantry squads are 7 men strong.  Regardless of their small arms (rifle, laser, etc), all infantry squads inflict 1 point of damage per 2 infantrymen to BattleMechs and Combat vehicles, and have an effective range of 600 meters (3 hexes; 6").  In addition, each infantry squad carries four one-shot man-portable SRMs.  Infantry squads cannot fire both their personnal weapons and their SRMs in the same turn.  Once fired, the MP-SRMs are expended and typically discarded.  When using MP-SRMs, an infantry squad can make up to four attack rolls against the same target, with each successful attack dealing 3 points of damage.  MP-SRMs have a maximum range of 1,200 meters (6 hexes; 12").

Construction

1.  Determine Tonnage:  unchanged.
2.  Determine Engine Rating:  engines mass one-half the amount shown on the table (round up to nearest .5 tons).
3.  Add Control Components:  unchanged.
4.  Allocate Tonnage for Internal Structure:  IS mass one-half the amount shown (round up to nearest .5 tons).
5.  Determine Jump Capability:  unchanged.
6.  Add Extra Heat Sinks:  heat is not used in this version of BattleTech.  Remove completely.
7.  Add Armor:  unchanged.
8.  Add Weapons and Equipment:  see weapons and equipment below.
9.  Complete Record Sheet:   unchanged.

Weapons and Equipment: 

Small Laser
Tonnage:  1.5 tons
Critical Slots:  1
Maximum Range:  1,200 meters (6 hexes; 12”)
Damage:  3 (1 vs. infantry)

Medium Laser
Tonnage:  4 tons
Critical Slots:  1
Maximum Range:  2,000 meters (10 hexes; 20”)
Damage:  5 (1 vs. infantry)

Large Laser
Tonnage:  8 tons
Critical Slots:  2
Maximum Range:  4,000 meters (20 hexes; 40”)
Damage:  8 (1 vs. infantry)

PPC
Tonnage:  12 tons
Critical Slots:  3
Maximum Range:  3,000 meters (15 hexes; 30”)
Damage:  10 (2 vs. infantry)

Flamer
Tonnage:  2 tons
Critical Slots:  1
Maximum Range:  600 meters (3 hexes; 6”)
Damage:  3 (triple vs. infantry)

SRM Rack
Tonnage:  1 ton
Critical Slots:  1
Maximum Range:  2,000 meters (10 hexes; 20”)
Damage:  10 each (2 vs. infantry)
Payload:  2 missiles

LRM Rack
Tonnage:  2 tons
Critical Slots:  1
Maximum Range:  6,000 meters (30 hexes; 60”)
Damage:  5 each (1 vs. infantry)
Payload:  5 missiles

Machine Gun
Tonnage:  1 ton
Critical Slots:  1 (includes ammunition)
Maximum Range:  600 meters (3 hexes; 6”)
Damage:  2 (triple vs. infantry)
Payload:  50 (MGs normally do not carry extra ammo, but if so it is figured at 100 shots per half-ton/crit slot)

Light Autocannon
Tonnage:  8 tons
Critical Slots:  3 (2 weapon, 1 ammunition)
Maximum Range:  2,000 meters (10 hexes; 20”)
Damage:  5 (2 vs. infantry; burst)
Payload:  20 (+20 per ton/crit)

Medium Autocannon
Tonnage:  12 tons
Critical Slots:  5 (4 weapon, 1 ammunition)
Maximum Range:  3,000 meters (15 hexes; 30”)
Damage:  10 (3 vs. infantry; burst)
Payload:  10 (+10 per ton/crit)

Heavy Autocannon
Tonnage:  16 tons
Critical Slots:  9 (8 weapon, 1 ammunition)
Maximum Range:  3,000 meters (15 hexes; 30”)
Damage:  20 (5 vs. infantry; burst)
Payload:  5 (+5 per ton/crit)

Gauss Rifle
Tonnage:  15 tons
Critical Slots:  7 (6 weapon, 1 ammunition)
Maximum Range:  4,000 meters (20 hexes; 40”)
Damage:  15 (1 vs. infantry)
Payload:  8 (+8 per ton/crit)

Anti-Missile System
Tonnage:  1 ton
Critical Slots:  1 (includes ammunition)
Maximum Range:  N/A
Damage:  N/A
Payload:  25 (AMSs normally do not carry extra ammo, but if so it is figured at 25 shots per half-ton/crit slot)

MRAS Artillery
Tonnage:  16 tons
Critical Slots:  10
Maximum Range:  18,000 meters (90 hexes; 180”)
Damage:  Varies according to warhead
Payload:  5

ECM
Tonnage:  2 tons
Critical Slots:  2

TAG
Tonnage:  2 tons
Critical Slots:  1
Maximum Range:  3,000 meters (15 hexes; 30”)

These changes should still allow the classic 'Mechs to be built, yet brings the game into a new era.

Enjoy!

MA