One of the most fascinating scenario idea potentials is the underwater environment for BattleTech or MechWarrior. This arena can be devastating to the BattleMech or its pilot. The first portion of this article will deal with the BattleMech and its pilot in an underwater environment. The second part will deal with the use of infantry underwater. The last section deals with the special equipment and troop types in this situation. As usual, all of these, when they depart from the Rules of Warfare, should be considered as optional rules variants.
The underwater environment adds an interesting limiting factor to all BattleMechs in slowing down their movement rates, cutting down on energy weapons, and lessening damage factors for various physical attacks. First let us look at movement in this arena. At the 0 level, a Mech is standing in the shallows of the area; it is not hampered in any way, nor does it have to make piloting rolls. In Level 1 water, it is around six meters deep.
It is slightly more difficult to maneuver; the simulation rules require 2 MP per hex because of the effects of water pushing on the Mech's surface at a greater concentration than air does when a Mech is out of water. A piloting roll at -1 is required to remain standing when a Mech first enters this level of water. If the pilot moves out of Level 1 and in again, he or she will be required to roll again. At Level 2 and greater, 12 meters and on, it costs the Mech 4 MP to move one hex. As the level changes, the pilot will be required to make piloting rolls. At Level 2, there is no modifier. At deeper levels the roll is made at a +1. This can be noted on chart 4, later in this article.
Now the next thing to be looked at is ranged weapons, energy weapons in particular. Because of the light-diffusing qualities of water, the range of energy weapons is shortened considerably. Chart #1 combines the BattleTech standard weapons with the newly-rediscovered Star League weapons chart.
| Chart # 1 Underwater Weapons Ranges | ||||
|---|---|---|---|---|
| Weapon Type | Minimum | short | medium | long |
| Small Laser | 0 | 1 | 2 | N/A |
| Medium Laser | 0 | 1-2 | 3-4 | 5-6 |
| Large Laser | 0 | 1-3 | 4-6 | 7-9 |
| ER Large Laser | 0 | 1-3 | 4-7 | 8-10 |
| PPC | 3 | 1-4 | 5-7 | 8-10 |
| ER PPC | 0 | 1-3 | 4-7 | 8-12 |
| Small Pulse Laser | 0 | 1 | 2 | N/A |
| Medium Pulse Laser | 0 | 1 | 2 | 3 |
| Large Pulse Laser | 0 | 1 | 2-3 | 4-5 |
A weapon source mentioned in the BattleTech Rules of
Warfare, but not fully developed there, is the torpedo. These are
simply underwater missile packs which have been designed to
function only in the underwater environment. Down below, they
are probably the most advantageous weapon. Chart # 3 covers
these torpeclos in detail so they may be added to a campaign.
The last item that should be covered is the rule that does not allow any non-energy weapon or flamer to be used underwater. Since this rules does limit the Mechs in choices to be used underwater, I would like to propose an OPTIONAL RULE whereby any non-energy weapon may be fired, BUT it must make a fallability roll before it is fired. This roll, in this particular environment, is a 9+ on 2D6 for the weapon to work. It the roll is below this minimum number, the barrel explodes, causing the loss of one critical space as mandatory; it is then useless for the rest of the scenario either in or out of the water.
The next part to be dealt with is physical attacks, either Mech vs Mech or naval vessels and submarines. The to-hit procedure is as per standard rules, but damage is handled differently. Punches do 1 point of damage for every 20 tons the attacking Mech weighs; kicks do 1 point of damage for every 10 tons of weight, while charges do 2 points for every 20 tons of weight times the number of hexes charged to the defender. (The charging attacker suffers 1 point for every 20 tons the defender weighs).
Clubs do 1 point of damage for each 10 tons of attacker's weight. Death From Above does 1 point of damage to the target for every 20 tons attacker weight times 3, and 1 point of damage to the attacker for each 20 tons of his own weight. These damages are resolved as is standard physical combat in the BattleTech Rules of Warfare.
Hull integrity must also be considered. To quote the Rules of Warfare again, "Whenever a unit that is underwater takes a hit, roll 2D6 to see if the unit's hull has been breached. If the result is 10 or greater, the damaged section has lost integrity and fills with water. For game purposes, treat that section as destroyed, Damage is not transferred from a flooded section until that sections Internal Structure is destroyed. If all a section's armor is destroyed, that section is automatically considered flooded."
So the rules governing Mech combat underwater have been covered. But there is a source of combat that can add another, completely new, dimension to the underwater environment. This source is the rules governing infantry, what they can and cannot do in this environment. Let us consider infantry, both in the BattleTech technique and from the MechWarrior/BattleTroops viewpoint.
If infantry is to be used in an underwater scenario, certain requirements must be met. The troops must be of veteran or elite status, and have had training in underwater combat. (Because of this specialized training they are three times as expensive as others of their ilk.) Only about one in twenty platoons are trained for this style of combat, always either Laser or SIRT troops. (SRTs are described in the New Weapons section.) See chart # 2 for ranges and to-hit numbers for these troops.
Damage is done as per standard infantry rules. Infantry does not have the same penalty to movement as the BattleMech. They move as per the standard movement rate listed for each type of infantry platoon. The foot infantry can be considered to be similar to the classic frogman or scuba diver; the motorized infantry used a type of sea sled to move them from point to point, and the jump infantry use an underwater propulsion pack which can for all practical purposes be treated as giving the same advantages underwater as a jump pack does on land. So much for infantry in BattleTech terms.
Let's take a look at the MechWarrior and BattleTroops version of underwater combat. This follow the same format of movement, ranged combat, and personal combat. Movement is simple. Swimming is done at 8 MP for standard movement, with one additional MP for every 2 levels of swimming.
One feature that must be added in this kind of scenario is current. To determine which direction a current is going, simply roll 1 D6, and that will tell you which hex side the current is coming from. When swimming fully with the current, a character moves 2 hexes for each movement point he spends, while when he swims completely against the current, it will cost him 2 MP per hex. Moving crosswise to the current takes 1 MP per hex.
In tidal waters, you must consider if the tide is incoming or outgoing. This tidal movement is only important to a mechwarrior if it's moving quickly or changes terrain, say from water to slick weeds equivalent to rough terrain. Assuming one moon and a standard planetary rotation of 24 local hours, roll 2D6. On a roll of 2-6, tide is outgoing; 7-11, tide is coming in; 12 is full tide.
The next thing to look at is the underwater terrain. There are innumerable types of terrain to be found in this environment. One of these is depth changes. If a soldier/character is in Level/Depth 4 water he has a choice which the much larger BattleMech does not have. He or she may be at any level/depth between 1 and 4, may be anywhere, vertically, in that three- dimensional space of water. This gives maneuverability, and adds to realism in that environment. It is suggested that a counter or small piece of paper with the appropriate level number on it be placed next to the soldier/ character, for quick reference and ease of bookkeeping. Since only trained troops are being discussed here, DEX rolls must only be made in cases of "running" movement from depth to depth.
The bottom level of any underwater area should be considered as rough terrain if any of the soldier/characters decide to walk rather than to swim. Other features that may be included are coral, seaweed, reeds, small underwater dunes, sinkholes, (consider all these as partial cover for line of sight and rubble/furniture for to-hit modifiers). In a rocky area underwater caves are also a possibility. Consider these as full cover.
In addition to these factors, coral has a possible 'tearing factor'. Make a 2D6 roll when going through it at the level where itis actuallypresent. If a 2 is rolled, the water suit/ light environment suit will take damage. Roll for location on the appropriate damage table. A good oceanography text can be of much assistance in imaginative creation of terrain hazards.
What ranged weapons that are usable in an underwater scenario? The weapons available range from crossbow/ speargun to man-portable torpedo tubes. Chart # 5 has a listing of the ranged weapons available to the character/ soldier in terms of both BattleTroops and MechWarrior in range and damage. The ranges are effectively halved because of the diffusion of light in the case of laser weapons, and because of the drag potential of water on the other weapons (except for the specialized torpeclos discussed in the next section). Damage has not changed on any of the weapons.
Grenades are not shown on the chart; they must be discussed separately here. If players wish to use grenades, there is a simple way to do it. For MechWarrior: halve your normal throwing range when throwing the grenade. Once it hits, even a miss-explosion, every character and NPC within 4 hexes must make a BODY saving roll at +4 to remain conscious, because of concussion effects through the water. Any character/NPC 5-7 hexes from the effect must make a BODY saving roll at +2, and anyone 8-10 hexes away must make a normal BODY saving roll to remain conscious. For BattleTroops: halve the range for the grenade throw, then give 6 points of bruise damage to anyone within 8 dots, 4 points to anyone between 9 and 14 dots, and 2 points to anyone between 15 and 20 dots away. Underwater, grenades are still deadly weapons - but they usually end up hurting the user more than the intended target.
Melee combat in the underwater environment depends
much more on skill and speed than brute strength. Few
weapons are actually good for this kind of combat; Chart # 6
deals with those that are most commonly used underwater.
When an attack is made, the target gets a +1 modifier on the to-
hit table because of the water's slowing effect.
Body location becomes very important at this point. If the weapon used is a bladed weapon, and if the character/soldier receives a head hit, on a 1-3 roll on 1D6, the weapon cuts the air supply of the character. If he/she is hit in the rear torso, on a roll of 1-3 on 1 D6 the air supply itself is hit. The affected warrior then has his BODY-2 in rounds to reach the surface (he must go one level/round to avoid things like nitrogen narcosis, or "the bends"). In BattleTroops terms; take the major Damage Potential and subtract 2; that is how long the soldier has to reach the surface.
We have been mentioning special troops. There is a fascinating possibility here, difficult to train, but excellent in underwater demolitions and anti Mech operations. We refer to trained aquatic mammals such as the Terran dolphin, which can be used to place explosives in strategic places, rescue divers in trouble (say someone whose air supply has been hit as above, who had also taken an incapacitating wound to the legs or underwater jump packs). They may also be used to retrieve items lost at sea or hidden on the sea bottom if the item is not too heavy. One of these mammals is equal to a squad of elite infantry in terms of antiMech operations. They are rare, so extremely expensive to train and to maintain. To train one of these mammals costs 2.5 million C-bills, the equivalent of a platoon of infantry. Maintenance costs are 7,500 C-bills per month. Remember, these are for a single creature. The benefityou getforthe expenses? In BattleTech terms, they move at 3 hexes per turn, attack Mechs as if they were antiMech infantry, and each aquatic mammal can do this twice per turn.
For BattleTroops or MechWarrior, the specialized mammal has 16 MPs, and as an attack a bite, which hits on an 8 or better on 2D6. The bite does 2D6 points of damage in the MechWarrior system, or 2L in the BattleTroops. For Mammal stats, generate a BODY, then take HTKfrom itasif itwereanormal human. These mammals are usually found only on their home worlds, due to the difficulty of transport.
Finally we come to the section on special equipment. There are two new or modified weapons for the MechWarrior/ BattleTrooper. The first is the man-portable Short Range Torpedo. The second is the bang stick. The weapons called torpedos are modified versions of the standard missiles which are designed to work only underwater. These have the same ranges as their land cousins and are equally deadly. These go by the designations of SRT pack, LAW-T, VLAWT, and Heavy SRT pack. The bang stick is a handheld weapon which electrically sets off a shotgun shell into a target when the front of the stick is placed on the target and the trigger is pulled.
Two of the most important items that the underwater combat soldier needs are a source of breathable atmosphere, and the classic wetsuit. The SCUBA (self-contained underwater breathing apparatus) is most commonly used for these soldiers. It weighs 8 kilograms; it will support a person for 4 hours of continued use. The wet suit ensures that the soldier will be ready for action by trapping layers of water between himself and the suit, which are warmed by his own body heat. It also dampens his I/R signature. This suit costs 75 C-bills.
One last piece of interesting equipment is a modified jump pack. This jump pack has been modified so that the scuba tank is set between the two jets; to keep it protected, it has a special armor plating put over it. The jump pack costs 10,500 C-bills with this modification.
It is hoped that these rules will add spice to your campaigns, as well as opening a new realm of adventure and combat: the underwater environment.
| Chart # 6 Hand-to-Hand Weapons Underwater | |||
|---|---|---|---|
| Weapon | Range | Damage | |
| BattleTroops | MechWarrior | ||
| Dagger | close | 1L | 1D6-3 (min of 1) |
| Sword | close | 2L | 1D6 +1 |
| Vibrodagger | close | 2L | 2D6 |
| Vibroblade | close | 3L | 3D6 |
| Stunstick | close | 1L | 1D6 -2 |
| Bang Stick | close | 4L | 3D6 +2 |
| (bang stick may only be used once per melee) | |||
BattleTech Rules in Underwater Combat
Punch Damage = 1 point for every 20 tons attacker weight
Kick Damage = 1 point for every 10 tons attacker weight
Charge Damage = Defender takes 1 point for every 20
tons attacker weight X hexes moved. Attacker takes 1 point for
every 20 tons defender weight.
Death From Above Damage = Defender takesl point of
damge for every 20 tons attacker weight X 3. Attacker takes 1
point for every 20 tons he weighs.
MechWarrior
Swimming MP = 8 for every 2 levels, a +1 to the MPs
Grenades used underwater (halve throwing range), rolls
for consciousness:
- 1-4 hexes Body Roll at +4 to remain conscious
5-7 hexes Body Roll at +2 to remain conscious
8-10 hexes Body Roll to remain conscious.
BattleTroops
Grenades used underwater (halve throwing range), rolls for consciousness:
- 1-8 dots 6 points of bruising
9-14 dots 4 points of bruising
15-20 dots 2 points of bruising
GU-2P Guppy Scout/Submarine
Tonnage: 2
Engine Rating: Pitban 20 .75
Cruise: 25
Flank: 38
Control Components: .1
Internal Structure: .2
Diving Equipment: .2
Armor Factor: 8 .5
Front: 2
L/R: 2/2
Rear: 2
Weapons & Ammo:
2 person cargo space .35
MNO-5W Minnow Submarine
Tonnage: 5
Engine Rating: Omni 25 .75
Cruise: 11
Flank: 17
Internal Structure: .5
Control Components: .25
Diving Equipment: .5
Armor: 16 1
Front: 4
L/R: 4/4
Rear: 4
Weapons & Ammo:
- Minnow Type A
Medium Lasers Front 1
Medium Laser Front 1
Minnow Type B
SRT-2 Front 1
Ammo SRT-2 (50) Rear 1
Minnow Type C
Small Laser R .5
Small Laser L .5
Medium Laser F 1
Minnow Type D
2 ton Cargo Pod L/R 2
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