GURPS BattleTech, working out heatsinks and the effects of heat buildup

[Ulzgoroth]

Originally Posted by Rupert

There's a very narrow band between "Cool enough it's fine" and "It's broken and probably blew up", not at all like BT's heat track. Also, only that one weapon (or engine) has the issue, again quite unlike BT.

As far as I can tell, BT's mech are some crazy piece of steampunk technology where someone, for some reason, ran the steam lines through the crew compartment and if you run the thing at 100% too long it literally cooks the crew.

Is BT's heat track long before stuff starts getting bad? Most computer renditions have made it that way, but my impression from more tabletop-adjacent sources was that the original rules started hurting you almost immediately.

High Tech's 'sustained fire' rules make the band where heat is a problem but permanent damage is only a relatively unlikely possibility twice as long as the band where heat is not yet a problem, and the band where the weapon is damaged but can continue to be used lasts indefinitely past that until the weapon is forced out of action by a rare 'mechanical or electrical problem' malfunction result.

As for localization of heat, it doesn't make much sense that missile launcher and autocannon heat buildup is even there, but for the most part you can attribute heating to the fusion reactor which obviously is plenty hot enough that its waste heat if not properly dissipated could damage surrounding not-a-fusion-reactor parts of the vehicle.

[Mark Skarr]

Originally Posted by Ulzgoroth

Is BT's heat track long before stuff starts getting bad? Most computer renditions have made it that way, but my impression from more tabletop-adjacent sources was that the original rules started hurting you almost immediately.

The PC Games do a bad job of reflecting the "realities" of BattleTech heat.

As few as 5 points of heat (on a 30-point scale) has you suffering -1 MP, which changes your walk/run dynamic (doesn't affect jumping). At 8 points, you start suffering to-hit penalties.

It can get rough. And it can happen fast.

14 is the first shutdown check (a 4+ on 2d6), but 19 is where it starts getting dangerous (your first ammo explosion check, again 4+ on 2d6). Which is why the smart kids avoid ballistic weapons like the plague.

If I'm loaded with energy weapons, I can overheat all I want and only have to worry about shutdown, not being visible from orbit in a visible-light spectrum.

But, unless your life support system is damaged, your cockpit may get uncomfortable but you won't fry. If it is damaged, your mileage may vary, but it'll likely be pretty short.

[Mark Skarr]

I love BattleTech. It's my favorite sci-fi world.

It’s important to remember that BattleTech was, originally, a sort of post-apocalypse sci-fi game. Where the world before was amazing and awesome, and now, you’re living in the rotting carcass of the Star League. In the post 3rd Succession War era (3025-3027 for those playing at home), the majority of humanity is supposed to be teetering on the verge of technological collapse. Most worlds don’t have access to fresh water. Sure, sector and nation capitals are fine, but, beyond that, in GURPS terms, they’re lucky if they’re TL5. TL6 is the standard across the more developed Inner Sphere worlds with access to some (up to TL12) high tech.

The 4th Succession War and the reveal of the Helm Memory Core put the game in an interesting place. Unfortunately, for us players, that information came out six months before the introduction of the Clans. The Clans (and everything since then) were, in my opinion, chasing power creep in the worse possible way.

But, originally, the ‘Mechs were supposed to be, for the most part, cobbled together and more bailin’ wire than actual actuator, so the hinky heat rules made sense. Keep in mind that vehicles don’t generate heat. Ballistic weapons generate zero heat on tanks/vehicles (not counting Aerospace Fighters, but that’s a whole other can of worms), and vehicles must have enough heat sinks to soak all of the heat from their energy weapons (if they have them).

Heat is a resource in BattleTech. It’s a way of pushing your unit beyond what it should be doing, but, there’s a cost associated with it. Do you want to be safe or do you want to have the ability to go out in a blaze of glory? Heat is really hard to emulate in other games, which is why, if I’m playing GURPS BattleTech, I just use GURPS for the character rules, and convert BattleTech from 2d6 roll high to 3d6 roll low. It works just fine.

And remember: it’s always ComStar.

[Fred Brackin]

Originally Posted by Ulzgoroth

Is BT's heat track long before stuff starts getting bad? .

Managing heat build-up is both an art and a science and I take accounts of pilots running their 'Mechs all out until they shut down or blow up to be entertaining fiction.

Some 'Mechs, usually light ones with light weapons only _can_ be run all out without heat issues. I don't think you can overheat a Locust before battle damage shoots off most of its' heat sinks and it'll be odd damage that only affects the heat sinks without killing the small and lightly armored Locust.

With big and heavily armed 'Mechs you just do a little dance. Suppose you'ver got a 75 ton Marauder with 2 PPCs (particle beams) a sort of odd large caliber "Autocannon" (fluff text makes it 120mm) and 2 Medium Lasers.

Range considerations make it inefficient to try and fire absolutely all weapons at the same time so mostly you do both PPCs (10 heat each) and the Autocannon (1 heat) on your first Turn of firing and then 1 PPC and the cannon and back to the 2 and 1 mix on alternating turns. You or your enemy probably run out of armor before very long.

Gambling everything by firing all your weapons every turn is impatience and bad decision-making usually.

[Kfireblade]

Originally Posted by Mark Skarr

I love BattleTech. It's my favorite sci-fi world.

It’s important to remember that BattleTech was, originally, a sort of post-apocalypse sci-fi game. Where the world before was amazing and awesome, and now, you’re living in the rotting carcass of the Star League. In the post 3rd Succession War era (3025-3027 for those playing at home), the majority of humanity is supposed to be teetering on the verge of technological collapse. Most worlds don’t have access to fresh water. Sure, sector and nation capitals are fine, but, beyond that, in GURPS terms, they’re lucky if they’re TL5. TL6 is the standard across the more developed Inner Sphere worlds with access to some (up to TL12) high tech.

The 4th Succession War and the reveal of the Helm Memory Core put the game in an interesting place. Unfortunately, for us players, that information came out six months before the introduction of the Clans. The Clans (and everything since then) were, in my opinion, chasing power creep in the worse possible way.

But, originally, the ‘Mechs were supposed to be, for the most part, cobbled together and more bailin’ wire than actual actuator, so the hinky heat rules made sense. Keep in mind that vehicles don’t generate heat. Ballistic weapons generate zero heat on tanks/vehicles (not counting Aerospace Fighters, but that’s a whole other can of worms), and vehicles must have enough heat sinks to soak all of the heat from their energy weapons (if they have them).

Heat is a resource in BattleTech. It’s a way of pushing your unit beyond what it should be doing, but, there’s a cost associated with it. Do you want to be safe or do you want to have the ability to go out in a blaze of glory? Heat is really hard to emulate in other games, which is why, if I’m playing GURPS BattleTech, I just use GURPS for the character rules, and convert BattleTech from 2d6 roll high to 3d6 roll low. It works just fine.

And remember: it’s always ComStar.

Huh, I'm not to familiar with the lore until around the fourth succession war and I never got the sense any world was so poor off as to be TL 5, hell, I never got the sense anyone was living at less the TL 7 at that point.

[Mark Skarr]

Originally Posted by Kfireblade

Huh, I'm not to familiar with the lore until around the fourth succession war and I never got the sense any world was so poor off as to be TL 5, hell, I never got the sense anyone was living at less the TL 7 at that point.

If you read the original BattleTech and BattleDroids they talk about it a bit, but MechWarrior 1st Edition goes into more detail. The characters--MechWarriors--are the exception to the world. They're supposed to be special. Many locations across the Inner Sphere (back in the '80's) was low-tech with a handful of commonly-found ultra-tech items. BattleTech doesn't really fit into GURPS's TLs. It spans a lot of them.

The release of the Helm memory core and the 20-Year Update they started retconning history. By the time the Clan invasion hit (and MechWarrior 2nd Edition--the best MechWarrior) they'd stepped it back because a lot of people didn't get the point and they wanted to chase power creep.

[Ulzgoroth]

Originally Posted by Mark Skarr

If you read the original BattleTech and BattleDroids they talk about it a bit, but MechWarrior 1st Edition goes into more detail. The characters--MechWarriors--are the exception to the world. They're supposed to be special. Many locations across the Inner Sphere (back in the '80's) was low-tech with a handful of commonly-found ultra-tech items. BattleTech doesn't really fit into GURPS's TLs. It spans a lot of them.

The release of the Helm memory core and the 20-Year Update they started retconning history. By the time the Clan invasion hit (and MechWarrior 2nd Edition--the best MechWarrior) they'd stepped it back because a lot of people didn't get the point and they wanted to chase power creep.

AFAIK mechwarriors are always an exception, even in the later days - mech units involve a ridiculously small number of combatants for their footprint. But the earlier content had more focus on most mechs being ancient and often hereditary personal possessions. Which has the problem of raising major questions about how you can continue having any of them if you keep destroying them in wars...

It's a bit hard to see why the limited working dropship and jumpship population would even bother to visit a world regressed to TL5-6, though.

[Not]

From House Steiner (FASA 1987):

We of ComStar are well-acquainted with the remarkable contrasts common to daily life in the Successor States. The average man or woman is by now used to incongruities such as using a cordless phone while riding a lumbering beast to the office or using food grown in a garden to pay for an appendectomy performed with a laser scalpel. Usually, it is only the more educated citizens who, having read of the glories of the Star League era, can see the irony of hunting their dinner with a bow and arrow and then watching their spouse cook it in a microwave.


Life in the Successor States isn't so bad. If you can cope with having to plow a rocky field because your agrobot lacks a cable six centimeters long, then you're perfectly suited to life in them there hills. If you enjoy the irony of zooming across the universe in a JumpShip, only to be forced to ride a jackass six klicks through a downpour, then man, you've got it made in these Successor States.

[Voren]

Originally Posted by Ulzgoroth

But the earlier content had more focus on most mechs being ancient and often hereditary personal possessions. Which has the problem of raising major questions about how you can continue having any of them if you keep destroying them in wars...

The fiction (and game rules) establish that mechs are highly salvageable and repairable, with just enough of a trickle of new production to hand wave away any difficulties. When that isn’t enough, someone (ComStar) will find (leak) an old (off the assembly lines on Earth) cache left over from the 28th Century (shipped yesterday) or whatever.

It's a bit hard to see why the limited working dropship and jumpship population would even bother to visit a world regressed to TL5-6, though.

The educational system collapsed with the end of the Star League and never recovered. Thus, in the older fiction we see dropships travelling to land on planets in other star systems on *water raids* since they’ve apparently never heard about comets.

Love Battletech, love the 3025 vibe, but a lot of it doesn’t make a lot of sense when you poke at it.

[Mark Skarr]

Originally Posted by Voren

The educational system collapsed with the end of the Star League and never recovered. Thus, in the older fiction we see dropships travelling to land on planets in other star systems on *water raids* since they’ve apparently never heard about comets.

It's hard to have a 'Mech battle over a comet, when you could have it over a water collection/purification plant. BattleTech is the realization of the Fallout trope: War never changes.

Originally Posted by Voren

Love Battletech, love the 3025 vibe, but a lot of it doesn’t make a lot of sense when you poke at it.

Seconded.

I had to pull up my copy of MechWarrior Destiny because I remember that they simplified 'Mech Combat (too much), but it had some really great ideas for moving it to other games.

Divide heat and heatsinks by 5 (round to nearest).
Weapon heat generates "tokens."
After heat dissipation, remaining tokens cause problems.
1 token = -1 to movement.
2 tokens = -1 to hit.
3 tokens = Shutdown (avoid 8+).
4 tokens = Ammo Asplode (avoid 8+).
5 tokens = Shutdown (automatic).

I'd do the change where your movement penalty is equal to your number of tokens, your to-hit penalty is equal to your number of tokens minus one, and go from there.

While I think MechWarrior Destiny went a bit too-far in their rules-light exploration, there's some really good ideas for porting BattleTech to other games.