Ive played different console adaptations of Battletech and I like them. Theyre a pain to get working on modern computers but still great quite fun when I do. In all of them a big problem is just ballistic weapons of all sorts. I understand that Ballistic weapons are supposed to be more realistic than lasers and particle beams so having them on everything makes sense. However from a gameplay perspective they do not. Theyre not useless but they fulfill a niche to contrast with those Lasers and Particle beam weapons.
In the Mechwarrior games having Energy weapons is quite important as missions are almost never 1-on-1 engagements like what the Clans wish for and design many of their battlemechs for. No the missions are rather long and having weapons that will run out at some point. One major flaw in that series of adaptations is that weapons are converted from their tabletop power to "DamagePerSecond" leaving some weapons almost useless as you have to continuously fire them. Ballistic weapons in particular suffer from that especially Machineguns. On the tabletetop a Machinegun can have 200 turns of shooting for only 1 ton of ammunition. The Clan Piranha is a particularly cheesy design having 12 Machineguns. On the tabletop that would have people ragequit. In a Mechwarrior Game you would run out of ammunition after or even before taking out one enemy.
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Energy Weapons have no ammunition concerns but require mounting enough heatsinks to actually keep cool. Range is another issue as depending on the Era the Particle Projection Cannon may be the only "long" range energy weapon available. Autocannon 5s are equal in range but Long Range Missiles beat them in range quite handily.
Extended Range energy weapons have higher heat buildup but also more range. On Inner Sphere battlemechs the additional range is by my opinion not worth it except for the Extended Range Particle Project Cannon.
For me the basic setup is to have either Large Lasers or Particle Projections on everything.
On the tabletop I favor designs like the Inner Sphere battlemechs, the Warhammer, Marauder, Flashman, and Awesome.
Clan technology improves Energy Weapons and battlemech builds around them massively. The Clan ER damage increases by up to 50% on ER PPCs. Clan ER Large Lasers outrange LRMs and most Autocannons. Clan Pulse Lasers double in range.
Clan have many more though some are actually overloaded with weapons especially Energy Weapons and not enough heat sinks to fire them all. The Nova, Warhawk, Supernova, and Dire Wolf are heavily equipped with Energy weapons and altering their loads makes them long-lived "laser boats".
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Nearly all Ballistic weapons have massive weight problems. They take up a lot of critical slots. They require ammunition that takes up more weight and slots as well as being vulnerable to ammunition explosions. They usually have low heat buildup which hopefully requires very few Heat Sinks.
In the Mechwarrior games Ballistic Weapons are just bad and lose out to Energy Weapons. Best I can get out of them is to try mounting one or two Ultra Autocannons or Gauss Rifles for extra firepower while Alpha Striking.
Strangely in Mechcommander 2 Ballistic Weapons are at their peak as by default all weapons have unlimited ammunition. Its easy to mount Autocannons on battlemechs with low heat limits and still perform very well.
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Missile Weapons are specialized by ranges but are pretty effective inside them as mounting more missiles is a simple method of mounting more tubes. Long Range Missiles are a heavy staple of many battlemech builds especially Clan LRMs that have a massive available range.
LRMs are just very good in most instances but they work best in conjunction with Energy weapons to conserve ammunition as well as compensate for the minimum range Inner Sphere Long Range Missiles have.
Multiple Missile Launchers for the Inner Sphere and Advanced Tactical Missiles for the CLans have greater versatility as they can carry multiple ammunition choices though they compete directly with the existing LRMs.
One major problem in campaigns that can be overlooked is that replacement Missiles can be quite expensive. For example an LRM ammunition ton costs fives times what standard AC-10 ton of ammunition does.
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I know there are tabletop builds that favor Ballistic Weapons as you dont need to worry about ammo in oneshot games. Pillager, Thunderhawk, Devastator and the like have powerful Ballistic Weapons so they can have massive fire power per turn. The backstory of the Devastator is stated to actually caused enemies to surrender through its massive firepower. Another assault class battlemech, the Annihilator has 4 LBX Autocannon 10s to just splatter targets.
So which do you prefer as your primary weapon, Ballistics, Energy, or Missiles?