It recently occurred to me that while there are many, many
Battletech Resources
on the internet, there are not very many mech design aids. Designing
battlemechs themselves is not difficult - anybody with a calculator and
some time can throw together legions of mechs. Designing good
battlemechs, however, takes a little practice, and since I just love to
design battlemechs, I thought I would release some of my own thoughts
and opinions on how to create good mech designs. Note that these are all
my opinions, and that they have been verified on the battlefield. If you
have different opinions,
then perhaps someday we'll meet and find out whose are better. :)
Everybody has their own favorite general design strategies:
Each of these has its place in the 31st century, but there are some key concepts that should be central to virtually all mech designs.
Damage: the amount of damage that a mech can dish out, per turn, consistently (ie, without massively overheating a la Warkawk P). Each of these is important.
A mech needs to have enough weapons to dish out a high numerical value of damage - the 3025 Charger, with its multiple small lasers, fails miserably in this respect.
A mech needs to be able to fire at least a portion of its weapons continuously. Part of this is heat management, but part is weapons redundancy - if a mech has one weapon, and it's knocked out, the mech is pretty much toast unless it's fast enough to run away. Also, weapons placement has a great deal of influence over how long weapons stay functional - those clan mechs with arms full of weapons may look nice, but halfway through the battle when those arms are shot off, the mech is practically worthless. Finally, you must consider the ammo supply - if a mech has ten SRM-6s, it has incredible short-range firepower, but with only one ton of ammo, that firepower will be gone in two turns. Allocate enough ammo so that your mech does not run out too soon.
Also, the way the damage hits the target is important. Generally, big chunks of damage (Gauss Rifle, AC20) are better than small chunks (small lasers, machine guns) because they increase the chance that you'll knock out a whole location, or the whole mech, in one shot. The large size of weapons that do big chunks of damage, however, limits their use. At the opposite extreme, lots of small hits (like multiple LB-X autocannons and SRM launchers) that give many rolls on the Hit Locations Table increase the odds that a possible critical hit will be rolled. This strategy is more effective when a mech of this type is paired with a mech that does big chunks of damage - the mech with big guns knocks off the armor, and the mech with lots of little guns gets lots of criticals on the now-bare internal structure. This is why LB-X autocannons with more than one ton of ammo are so great - they can fire standard shot to knock big holes in an enemy mech's armor, then cluster shot to get lots of criticals.
Not only does a mech have to be able to do a lot of damage, but it also has to be able to hit with its weapons. Pulse lasers, available with level 2 technology and up, are great at this, although the shorter range of the Inner Sphere version is a hindrance. (Not an overwhelming hindrance, however; it is possible for an Inner Sphere Penetrator, with six Medium Pulse lasers, to go toe to toe with an assault mech and give as good as it gets.) Clan targetting computers also greatly help a mech to hit with its weapons. The (in my opinion) single most devastating FASA-designed mechs are the Goshawk and Viper, two clan mechs that combine targetting computers with pulse lasers.
If you don't have access to pulse weapons or targetting computer, the next best way to get good to-hit rolls is to use long-range weapons. At long range, your to-hit rolls won't be any better than your opponent's, but if you continue to fire your long-range weapons while you are at medium and short range, your to-hit rolls will be great. If you have PPCs and medium lasers, don't start firing the medium lasers until the range is 3 or less, unless you have the extra heat sinks (see below for my thoughts on this).
Heat dissipation: how much heat can it dissipate? A mech can have all of the weapons in the world, but if it can't fire them, they're useless. A mech should have enough heat sinks to fire all of its weapons of a similar range together. If you have four PPCs, but only enough heat sinks to fire three, then the fourth is redundant. Similarly, if you have two PPCs and a bunch of medium lasers, having the heat sinks to barrage everything at once does little good, since the optimum range for the PPCs is different from the optimum range for the medium lasers.
Armor: how much damage can it take? Armor is cheap - even standard armor
gives you 16 points per ton - so there is no reason not to maximize your
battlemech's armor. You can sometimes get away with reducing the
armor on the legs or arms, but since it's so light, you might as well max
it out - and someday you might thank your lucky stars that you put those
extra 4 points on each leg.
Designing and playing with 3025-era technology is a great way to start out your Battletech experience. I'm convinced that a person who can design great 3025 mechs will, as long as they think carefully, be able to design great Level 2 and Level 3 mechs.
The key is efficiency. With standard heat sinks, the ability to dissipate enough heat to fire all of your weapons simultaneously (alpha-strike) is too expensive in terms of tonnage. The best idea is to go with several ranges of weapons, keeping the ability to dissipate any one or two groups simultaneously. A good example of this is the 3025 Stalker - at long range, it can fire the LRMs. At medium range, it can fire the Lg. Lasers, and at short range it can fire the medium lasers and SRMs. These range groups overlap somewhat, enabling it to make maximum use of its heat dissipation ability, regardless of the range.
Of course, not all mechs are big enough to have a wide variety of weapons, and a particular role might lead to a particular weapons complement. The key to remember is that you want to be able to dissipate all of the weapons of a certain grouping, and that a grouping is usually less than the mech's total complement. This is pretty common-sense: if a mech has LRMs and medium lasers, it doesn't need to have the heat sinks to fire all of them; but it should have enough heat sinks to fire all of the LRMs in a group, and all of the medium lasers in a group.
The advantage to standard heat sinks is that they are small enough to be placed in a mech's legs. If you are not using the legs for anything else, you're better off putting heat sinks there, since they get double-dissipation when submerged.
In terms of weight, damage and heat, medium lasers are the most efficient weapon in the game. Medium lasers are great for massed secondary weapons. SRMs are often used with medium lasers, but I do not consider them to be equals. If you have lots of extra tonnage, you may want some SRMs, but unless they're massed (as in the SRM Carrier) their critical-hunting abilities don't compensate for the efficiency of medium lasers.
PPCs have good range and damage, but you can't have too many of them and expect to keep up a continuous rate of fire. I consider them good singly, on medium mechs with lots of short-range firepower and 5/8/5 maneuverability, as in my HTC-5TC Hatchetman variant which, while using some 3050+ technology, still illustrates this principle. If you have more than one PPC, as the Warhammer and Marauder do, you need lots of heat sinks, and probably don't mount many more usable long-range weapons. (The Marauder mounts an additional AC5, but it can't use all of its long-range weapons effectively, because it doesn't have enough heat sinks.)
Long Range Missiles are good low-heat long range weapons, but some are better than others. In terms of tons per missile, the LRM 5 and LRM 15 have an advantage over the LRM 10 and LRM 20, but the LRM 20 has the advantage in heat points per missile. If you are mounting two LRM 20s, consider sacrificing a couple of tons and mounting three LRM 15s. If you have lots of heat sinks, use eight or ten LRM 5s. It's annoying to roll on the missile hits table so much, but the additional firepower makes it worth it.
In 3025, the amount of critical spaces that a weapon takes up is not extremely important, since the lack of advanced construction materials leaves lots of open space. There are reasons not to mount lots of big guns, but low space usually isn't one of them. Usually, the torsos are the best place for weapons, since they tend to survive the most.
In 3025, the placement of ammunition is critical, since if ammo is hit, the mech is usually dead. The most often-used ammo storage areas are the torsos; this is logical, because torsos tend to have lots of armor. However, there are probably better locations. If you only have small amounts (< 10 shots) of ammo, it's probably ok to put it in the torsos, since it will probably be all used up by the time the mech takes serious torso damage. If you only have one ton of ammo, the head is a good place to put it, since head hits are so rare (and if you're hit there, you're not in good shape anyway). Possibly the best spot for placing ammo, however, is the legs, since they tend to have lots of armor, and are not hit as often. Plus, if ammo in the legs explodes, it is farther away from the CT, and the mech is more likely to survive.
If you must put ammo in a torso or arm, be sure to "pad" the area with
other items, so that if a critical hit is rolled for that location, the
odds that the ammo is hit are reduced.
Level 2 Inner Sphere technology provides you with a lot of opportunities that are not present with Level 1. There are three main groups of advanced technology: advanced construction techniques, advanced equipment, and advanced weapons.
The advanced construction techniques available in 3050+ are Extralight (XL) engines, Endo Steel internal structure, Ferro-fibrous armor, double heat sinks, and Triple Strength myomer.
At first, XL engines seem like a gift from the heavens. They usually allow a mech to move faster and carry more weapons, or carry lots more weapons, or move lots faster. For mechs with certain roles, this additional speed and/or weaponry may be necessary, but I think that XL engines are horribly overused. Their advantages are large, but in my opinion, their disadvantages are larger:
What, you say? Only two disadvantages? For now, let's ignore cost, since many people don't really regard cost as a factor in mech design (which is unfortunate). I think that the extra criticals by themselves negate most of the value of having an XL engine. Essentially, the 3 extra engine crits in each side torso mean that if an XL-equipped mech loses a side torso, the mech is knocked out of the game. Some would say that if the mech is faster, or has more weapons, then it is more likely to survive, but when I play the XL-equipped mechs are usually the first target (since they're so easy to knock out).
Of course, there are uses for XL-equipped mechs - reconnaissance is one, and raids behind enemy lines is another - in these two cases, having mechs that are fast is a priority. Rapid-response battlefield forces is a third category of mech that would benefit by the use of an XL engine - mechs designed to rapidly exploit enemy weaknesses or holes in the enemy line. Note that general line-of-battle heavies and mediums suffer from XL engines, since their job is to absorb as much punishment as possible while remaining combat-ready.
Whether or not XL engines are appropriate for assault mechs is a hotly debated topic, although I don't know why. Assault mechs are already expensive, and since they should be protected by other mechs anyway, it's okay if they're a little more vulnerable, right? Wrong. In my opinion, the high cost of assault mechs means that they should not use XL engines, which would only increase their cost more. Since assault mechs are so big, they have more than enough room for weaponry already, lessening the value of the XL engine. Since assault mechs are so expensive, they should be as invulnerable as possible. You don't want your most expensive unit to die any faster than necessary. (Plus, assault mechs without XL engines tend to be cheaper than heavy mechs, and even some medium mechs, with XL engines.) Yes, all those designs in TR3058 with multiple Gauss Rifles are nifty, but if the designers would have dropped a Gauss Rifle and un-XL-ed the engine, they would be able to afford two mechs for the price of one.
Endo steel internal structure and ferro-fibrous armor are similar. Endo steel internal structure weighs half as much as normal internal structure. (Some people round up to the half-ton, some don't. Some official FASA mechs round up to the half-ton, some don't. Technically you're supposed to, but I don't.) Ferro-fibrous armor increases the number of points per ton of armor from 16 to 17.92. Each costs 14 additional critical spaces, which can occur anywhere on the mech (arms, anyone?) and, when hit by a critical hit, are treated as an empty slot.
While both endo steel internal structure and ferro-fibrous armor will save you weight, endo steel will save more. Using both on a mech is possible, but it tends to use up most of the free critical spaces. Light mechs can easily use both, since they seldom have enough equipment to fill up all of their critical slots; some medium mechs can fit both, and a handful of heavy mechs, but if an assault mech has both endo steel and ferro-fibrous armor, I don't want to pilot it. :) The advantage ferro-fibrous armor has over endo steel is that of field refits - it is a lot easier to upgrade an existing design in the field to use ferro-fibrous armor than endo steel internal structure. (Plus, in order to manufacture endo steel, you need an orbiting refinery, which only a few planets have.)
Double heat sinks are possibly the single best improvement that Level 2 tech has to add to Level 1. Double heat sinks weigh 1 ton, take up 3 critical slots, and dissipate 2 points of heat. If a mech has some double heat sinks, all of its heat sinks must be double strength. Double heat sinks do not affect how many heat sinks fit inside the engine, and 10 heat sinks still come free with the engine. Realistically, there is no reason why any level 2 mech should not use double heat sinks. (There are some mechs that do not build up even 10 points of heat, but the extra cost is minute, and the mech might someday have two engine criticals and need the extra 10 points of heat dissipation.) Double heat sinks enable a mech to fire many, many more weapons. They are invaluable.
Triple Strength Myomer is an odd fellow. It takes up six critical slots
and no tons, and increases the cost of a mech substantially. Basically,
when the mech overheats by 9 or more, it moves faster and does more damage
when it physical attacks. I have never been much of a physical attacks
person myself, and I think that the negative heat effects (like additional
weapons fire to-hit penalties and risk of explosion) balance out the value
of TSM. If you're playing in a game that does not use cost, and you have
six crits free, you may as well put it in, just in case you end up
massively overheating, but it is probably unwise to make it the main
attack strategy of your mech. (Face it, anything with multiple melee
weapons gets taken out asap anyway, and if your 100-ton mech does get in
its 40-point hatchet attack once, it won't twice.)
There is a lot of advanced equipment that is available with Level 2 technology, and most of it is not very useful.
Beagle Active Probe - detects hidden mechs and vehicles. If you are not using hidden units, it is useless.
Guardian ECM Suite - similar to the Beagle Probe, the Guardian jams enemy electronics, negating the effects of Beagle Probes, Artemis IV, and Narc Missile Beacons. Effective if those are in use; not effective if they're not.
Target Acquisition Gear (TAG) - range of a large laser, mass of a medium laser, no heat, no damage - basically a target designator for the Arrow IV missile artillery system. If you're using Arrow IVs, TAG helps; if not, it's wasted space.
Artemis IV Fire Control System - makes LRMs and SRMs more accurate, but is only really worth the tonnage on LRM 15s and LRM 20s. Does have the benefit of increasing firepower without increasing heat.
Narc Missile Beacon - completely worthless. Makes missiles more accurate, sometimes, but rarely if ever is effective.
Cellular Ammunition Storage Equipment (CASE) - probably more of a construction option than equipment, CASE seals all of the ammo in a torso into a box. If the ammo (or Gauss Rifle) explodes, and does enough damage to transfer, the excess damage is blown out the rear of the mech. The side torso is still destroyed (and its accompanying arm), but the mech is still alive, provided that it didn't have an XL engine. CASE only works in the side torsos, although it does channel out ammo explosions that started in an arm or leg.
C3 computers are definitely one of the more interesting items available with
level 2 Inner Sphere tech. Very interesting indeed. I think that if C3
networks are used properly, they can be extremely devastating - ie, fast,
extremely agile and heavily armored mechs (without XL engines!) that use C3
slaves to close with enemy forces, and slower mechs with C3 Masters, C3 Slaves,
and lots of long-ranged weapons (even medium-ranged; standard PPCs work
great!), make an effective team. The obvious counter, however, is to simply
have all of the opponent mechs use Guardian ECM suites; if they know you're
using C3, and they can reconfigure their mechs (as omnimechs can), the
effectiveness of your C3 network is degraded. This is why I usually don't use
C3 networks, although occasionally it's fun.
There are several classes of advanced weapons that are now available:
Pulse lasers are similar to standard lasers, but weigh more, do more heat, give more damage, and have shorter ranges. Their advantage is that they have an automatic -2 to-hit modifier. Sometimes this is worth it, but seldom, in my opinion. In one on one duels, however, it can be the key - this is how a Penetrator can defeat a Thunder Hawk.
Extended range lasers are similar to standard lasers, but do more heat and shoot farther. Sometimes they are good to have, but not always; I prefer ER PPCs, but I don't always have the tonnage or the heat dissipation ability.
Extended Range PPCs shoot farther than normal PPCs, and do 15 heat - quite a lot, but if you have extra heat sinks, they're worth it. They cost more too, but everything good has a cost associated with it.
Streak short range missiles weigh more than standard ones, but the to-hit roll for a streak SRM represents the targetting system, attempting to achieve lock-on. If lock-on is achieved, the SRM fires and all of the missiles hit; if lock-on fails, the SRM does not fire, use up ammo or build up heat. They're more efficient, and if you have the tonnage, you might as well go for it.
Gauss rifles are extremely devastating weapons. They're big, but their high damage, long range and low heat make them excellent weapons. They work well when paired with ER PPCs and in refit kits, upgrading Autocannon 20s. Savvy designers can fit multiple Gauss rifles on heavy and assault mechs without using XL engines; can you?
Arrow IV missile artillery is also extremely devastating, though
short-ranged (by artillery standards). It does lots of damage, but builds
up lots of heat and, worst of all, takes up 15 critical slots. Since it
is so light, it does fit well on hovercraft and slow VTOLs and moderately
fast mechs, but you can fit two on a upper-weight heavy to assault mech.
Clan technology is the most advanced level 2 technology available. Basically, anything that the Inner Sphere forces can do, the clans can do better (with the exception of C3 computers and Triple Strength Myomer).
Since Clan XL engines only take up 2 criticals in each side torso, instead of 3 like the Inner Sphere version, they are not nearly so bad. A clan mech without an XL engine (such as the Warhammer IIC or Marauder IIC) will still be able to survive longer than a clan mech with an XL engine, in most situations. Also, since the clans do not worry about cost, the role of XL engines in clan mechs is wider than in Inner Sphere ones.
Clan Endo Steel internal structure and Ferro-fibrous armor now take up half as much space as their Inner Sphere equivalents, which enables a lot more mechs to carry both. Unless there are other concerns (like the need to carry lots of heat sinks), most heavy mechs have the critical space for both endo steel and ferro-fibrous armor. It is unfortunate that more FASA-designed mechs do not, but on the other hand, it is fortunate for the person who fights their custom design against official book designs. Also, clan ferro-fibrous armor gives 19.2 points of armor per ton, which is an additional advantage. (Endo Steel is still more efficient, however, but only by a small amount, depending on the size of the mech.)
Clan double heat sinks only take up two criticals, so it is possible to fit them in the legs. This is a Good Idea. Because of their small size, it is possible to fit a lot more heat sinks on a mech - it is not unusual to see an assault mech dissipate 40-50 points of heat. The firepower that this makes possible is incredible. So incredible, in fact, that many people are overwhelmed and do not take advantage of all of the possibilities.
Clan advanced equipment is similar to its Inner Sphere counterparts. In a few cases, an item is smaller and/or has an increased effect (for example, the ECM Suite). Clan CASE takes up 0 tons and 0 critical spaces, which is convenient, and it can fit in the arms, legs and head (although you tend not to see too many mechs with CASE in the head).
Clan weaponry is extremely devastating. In summary, clan weapons tend to weigh
less, do less heat, shoot farther, do more damage, and take up less critical
space than their Inner Sphere counterparts.
This area is on hold until I playtest Maximum Tech some more.