"Best rationale for big stompy robots?" Topic

I played some Battletech back in the 90's. We ran a campaign, designed our own mechs, etc. But I always had an issue with Anthropomorphic tanks over….tanks.

What's your best rationale to make mechs viable? What sci-fi reasoning makes sense to you?

Best I can come up with is, just cause they are cool.

Xin

Cool factor.
Intimidation factor.

"Real Life" reasons---
the more elevation you have the further out your range of visibility is.
Mobility--sure treads and wheels are fast, but the ability to jump or straddle a barrier would be a game changer

I think it could be a natural progression from power armour. The armour gets heavier the weapons bigger. Just like tanks did in WW2.

They make no sense at all. But they can sure look cool.

Frankly, I think drones are the next big thing. Imagine a drone carrying a small shaped charge. Lands on a vehicle/mech, attaches with magnets or suction cups and BOOM.

Mechs are tall targets – no such thing as "hull down." I knew one gamer who liked to refer to them as "missile catchers." Barriers are not that big a deal, and you'd start seeing anti-mech barriers instead of anti-tank barriers. How about lots of cables designed to snare/trip the thing. Leg joints look very vulnerable unless you armor the crap out of them, but then they lose a lot of range of motion….and so on.

Depends on the setting. In Battletech:

1. Mechs can be dropped directly from orbit
2. Mechs work in all environments and in a vacuum
3. Mechs only require one crew member to operate effectively
4. Mechs can pick their way over otherwise impassable terrain
5. Mechs with manipulators can carry objects

And so forth and so on. Mechs are just better, because it's Battletech.

If you're talking more generically, you need to define what you mean by mech. You've got 30-foot tall Battlemechs, 15-foot tall Gears/Votoms/Landmates, giant AT-ATs, skyscraper sized Titans, stuff that is basically a modern tank with legs…. All of these have different possible justifications, and different strengths and weaknesses. Gears absolutely can (and do) go hull-down in cover all of the time, for example.

In general the most usual justification is better all-terrain performance.

If the mechs have manipulators then the ability to rapidly swap/adapt payload might also be valuable.

Mechs on the smaller end might even buy you a useful compromise between infantry and a small armored vehicle.

Some of this also depends on other tech; if you have grav-tanks of some kind then mechs probably don't really have a niche to fill.

-Will

They are cool. Do you need another rationale?

Never use them in my games. The concept has always bugged the crap out of me.

In Metal Gear, they were specifically for launching nuclear missiles from terrain regular launch vehicles could not enter.

Also a walker can have arms so it can punch giant monsters :-)

Yes, if you live in a universe where martial arts beat guns you need vehicles that can do kung-fu!

-Will

They can stomp all the tiddly tanks and/or use them as roller skates.

Wminsing has been drinking deep from the mug o' truth :)

The Rule of Cool.

I have to disagree with many of the above posters. My personal reason (and I admit it's just an opinion) for why I don't (and can't) play battletech is because it ISN'T "cool" – it's dumb.

I always thought Battletech looked cool but the games got bogged down in endless record keeping. But that was the state of rules when it came out.

I must also admit that as cool as they looked, the whole concept was really dumb.

Also Rule o' Cool.

Drones are boring. 'Mechs are roughage for too much hard sci-fi.

With Extra Crispy. They're not about rationality: they're about cool. Of course, I play no games which have such things. My rationality keeps getting in the way of my cool.

The best rationale I have seen for 50-foot tall 'mechs is the need to fight 50-foot tall aliens.

I think from a scientific rationale perhaps the mech was the smallest offensive platform that shield generators could be practically installed into making the others like tanks etc obsolete except in swarm scenarios.The tech level also could make it impossible or too expensive for certain civilisations to create or even copy.

I'm with Extra Crispy. They just look cool. I don't actually use them because they don't make sense.

I have 3 or 4 stompers in my 6mm settings…..3 are smaller recon walkers……quiet and stealthy approach compared to squealing tracks and better visibility……the biggest one is for spaceport defence, a big mobile gun turret in effect that can wander around and act as a ground tug or recovery robot too……..I have a faction of walker robots too but they always seem to get creamed on the tabletop!!

Because we heard the opposition was about to deploy a huge Ogre, and the president was a former D&D player.

For justification--maybe they evolve from agricultural uses or manned loaders in logistics centers? Quick, put some guns on that sucker and get out there! That starts a mech gap race until finally one non-mech using star nation bankrupts its opponents who buy mechs on the wrong side of the cost benefit ratio.

It takes a MechaGodzilla fight Godzilla!

mecha up to about 20 feet tall should be able to go prone and otherwise take advantage of cover like an infantryman, while carrying tank-scale guns.

Also, a small-ish mecha is much lighter and potentially easier to deploy.

Bigger mecha don't really make sense in an atmosphere, but do make some sense in zero gee, as the mecha can shift it's center of gravity around it's thrust axis and use less reaction mass to maneuver.

They will grow out of power assisted armour for infantry.

So instead of walking one will sit in and drive them, but size is going to top out at around 10 to 14 feet.

And while I'm at it, walking combat armour suits are still more realistic than either hover or grav tanks; the former because power to weight ratio versus lift, and the latter because we don't have the first clue how to produce anti-grav.

> In general the most usual justification is better all-terrain performance.

Which only makes sense if a mech never has to cross soggy ground.

The sad part is any justification for them falls apart under any kind of logical analysis. Rule of Cool is good however.

And while I'm at it, walking combat armour suits are still more realistic than either hover or grav tanks; the former because power to weight ratio versus lift, and the latter because we don't have the first clue how to produce anti-grav.

Yea I always laugh when people say mechs are impossible but anti-grav makes sense; we have some idea of how to build a mech, while anti-gravity is currently pure magic.

I mean, if you're trying to be perfectly realistic just about every trope we usually associate with science fiction is pretty implausible. Space fighters make rather less sense than mechs but everyone loves them!

-Will

Which only makes sense if a mech never has to cross soggy ground.

Not really true; it's all about ground pressure, and with clever design the mech should be able to have ground pressure not much worse than a tank. Plus if it gets bogged it has arms to help work the mech out.

-Will

They can crouch, crawl, climb, swim, dig into and move through swamp.
In contrary to anti-grav/hovercraft, mech is more resilient to EMP, has less heat and acoustic signature, use less energy to stay in place and can change the elevation.

Mechs always have worse ground pressure. Think dynamic as they stride, not static. As you make the "feet" bigger, they have more trouble fitting into tight terrain and just walking around gets more and more awkward.

It's not just soft ground that's a problem: it's urban terrain. One of the problems with powered armor is that yo quickly start falling through floors …

If you've been following the 2nd season of Gundam Iron Blooded Orphans, a mobile armor is a large self operating machine no pilot. It has a swarm of smaller drones following it. Mobile suits were made to fight mobile armors. A giant robot isn't much more than a large suit of powered armor to an extreme.

But it surprise you to know the creator of Gundam originally envisioned the mobile suits as more of powered armor than giant robots, but Sunrise wanted them big. Sells more models.

Practical? Only if they can make them work like they do in series like Gundam. Otherwise they're a big target.

Anthropomorphic mechs -- particularly the ones that looked like ninja or samurai -- never sat well with me. I like big robots as much as the next guy, but for me Mechs only make sense when they look like walking gun platforms.

Which only makes sense if a mech never has to cross soggy ground.

Again, ground pressure. A mech that is twice man-height will probably weight in about 2-4 tons (simply being 8x man-weight puts it about 2400lbs). In order to get ground pressure down to the same as your grunt infantryman, ~5lb/in^2, you need feet that are kinda big, but not obscenely so. 4 tons is 8000lbs, so 5psi ground pressure makes for feet covering 1600in^2 (ok, 2x800in^2). That's 40x20" for each foot.

> Not really true; it's all about ground pressure, and with clever design the mech should be able to have ground pressure not much worse than a tank. Plus if it gets bogged it has arms to help work the mech out.

No mech I've ever seen in anime works, combat suit yes, mecha no.

> 4 tons is 8000lbs

4 tons is a joke when talking about mecha like a Gundam or the 20 ton mechs (minimum) in battletech. Sorry – but the engineering needed to make them useable would be better used on something with tracks or bulbous wheels instead.

I've loved giant robot mecha ever since I saw robotech as a kid back in the 80s. But out side of sci-fi settings powered by the rule of cool I can't really see them being practical weapons of war. Ok maybe we might see some industrial mechs and at best. And if mechs were to become weapons of war I think we'll be looking at stuff like the only current real world mechas, the Japanese kuratas and its American counterpart the Megabot

oh here is a interesting question, why can some people accept space combat that looks like WW 2 naval combat but a 20 foot tall robot that can move and operate like a infantry man is too far out?

Granted, the bigger mechs (like a 12m tall Battlemech or 18m tall Gundam) don't make much engineering sense, at least in a Grav field. You will notice that most Gundam stories take place in zero-gee.

I was specifically talking about the smaller mechs like the VOTOMs or Gasaraki Tactical Armors, which are 3.5-4.5m tall. Or the Heavy Gears from DP9. Those are probably the biggest functional mechs you will see in ground combat.

"Best rationale for big stompy robots?"

You need something to battle Ork Gargants on equal terms… ;-)

THIS:

"The best rationale I have seen for 50-foot tall 'mechs is the need to fight 50-foot tall aliens."

In one.

To put it another way: A weapon comes into existence to combat a threat, or operate in an environment, for which existing weapons are impractical, impotent or disadvantaged.

ANY fictitious weapon system, in ANY setting, must have a rationale, or no matter how 'real' it looks, nor how 'cool', it fails the First Law of Good Sci-Fi; Thou Shalt Suspend the Disbelief of Thine Audience.

'Walking gun platforms' (and most Battletech Mechs are these) are amongst the worst violators of this principle. Setting aside BT's now very dated rules concepts (and oddly short ranges) for a moment, the obvious inability of most Battlemechs to bend at the waist or reach to touch the ground is a woeful slap in the face to realism. Bipedal lifeforms (let alone machines) can't function if they don't have the ability to right themselves when they fall flat on their faces.

Stubby arms packed with guns and missile launchers aren't going to get you back on your feet, and who believes the battlefields of the future will be billiard-table smooth? ;)

In truth, the question of the size of mecha is entirely dictated by what you want them to do. There's no difficulty in envisioning giant, walking tanks; the technology is possible, and there's no breaking (or even bending) of fundamental physics, as there is when you stick a warp drive on a starship.

Within the current envelope of military technology a 'walking tank' is senseless because it is likely to be too tall to survive the 'he who shoots first, wins' combat environment, but there is no guarantee that this will always be the case. As the constant battle between missile and armour tech rages on, we may see materials that are light enough and resistant enough to justify their use in humanoid power armour, which may evolve into mecha.

Fast forward a few hundred years, and who knows? There's no law of evolution that dictates that intelligent life must be a biped about 5' 6" tall. Supposing we DO encounter a hostile race of giants, and 40 foot tall mechs are the only way to meet them toe-to-toe?

Another thing to consider – the most natural thing for a human to interact with is a machine that mimics their own actions. A weapon system that copies one's raising a rifle to shoot, or turning one's head to scan the horizon, has massive advantages over an equally armed and protected system which requires its operator to act artificially, pushing buttons and looking through scanners, pulling levers and generally moving in a way that is unnatural.

Imagine if you could create a machine, equal in firepower and battlefield survivability to a tank, but requiring only one crewperson, trained to no greater level than the average infantryman? Why so little training? Because the machine wraps around the operator, repeating all their movements on a far greater scale. There are no buttons or levers; the operator's body is the interface.

Instantly, you have a huge strategic advantage; your enemy needs to train four or five people to work as a seamless whole to get the best out of their lumbering tank. Your mecha allows you to train four or five guys to crew four or five 'tanks'!

Mecha don't have to be 'superweapons'; witness the majority of Mobile Suits in the first Gundam conflict, the One Year War; these behemoths are mostly 'poor bloody infantry' writ large. They still die in droves, hate artillery, and dive for cover when air support screams in.

In Armoured Trooper Votoms (and its game-child, Heavy Gear) the mecha are too big to call 'power armour' but not mega-huge monsters. They often work as part of a combined-arms strategy, alongside infantry, tanks, APC's and all the other inventions of death we humans are so good at building.

Its the setting, and the stimulus for war, which provides any plot device weapon with its rationale. Get that right, and I'll buy into your Mecha fantasy, no matter how big.

No mech I've ever seen in anime works, combat suit yes, mecha no.

Yea but the question is about Mechs in general, not just anime mechs. Plenty of other sources have mechs that attempt to address these issues. Heavy Gear sized mechs as Lion in the Stars points out weigh 4-10 tons, not 20+. They also have the advantage that their primary combat environment is bone-dry. :)

oh here is a interesting question, why can some people accept space combat that looks like WW 2 naval combat but a 20 foot tall robot that can move and operate like a infantry man is too far out?

Yep mechs are dumb but my tiny little space fighter can somehow take out a space battleship better than an unmanned missile and that makes perfect sense! ;)

Basically this question boils down to everyone has their own preferences in what they are willing to hand-wave away in science fiction!

-Will

I played with some simple math last night, got really bored. For a 40 ton battle mech to get 12 lps/sq. Foot ground pressure, it only needs a 5ft by 8ft foot. That should match a human weighting about 300 pounds standing on one 3 inch by 8 inch foot.

People are forgetting that armor and tech will evolve, and if a mech becomes a viable platform, with ECM, better armor materials, more efficient power plants, camo tech, etc, then why not? It seems the detractors are using modern tactical doctrine as the standard to go by…

I'd have to agree with Raptor. The smallest viable platform for a shield generator. The next biggest thing in my sci fi universe would be a starship or structure

Reality ruins all games.

i use BT with Traveller. Pre-grav TL. I'm thinking of designing 30'-40' alien creatures for them to battle, some type of bio-borgs. The Clans I use as Second Man, genetically enhanced, throw out the duelling code. I use most of the background, just add more Dune&Game of Throne politics. The known stars are all recovering from three interstellar wars so when not fighting they're construction/recovery/agricultural enablers. Manufactories, farmland etc. must be captured, not destroyed-like the Seven Years War trying to prevent the destruction and decay of the Thirties Year War. The new books have civilian vehicle construction(trains, airships) and a undersea campaign is easily done.

The other that's just as well done is Heavy Gear, et al.

So stop promoting paralysis by analysis, jump into a cockpit or suit up and "Light 'em UP!!!"

R. Lee Ermey would make a great MechWarrior.

Or, instead of fixating on the tropes and things like BattleTech one could extrapolate from current technology.

So no mechs forty foot tall etc. or weighing four or more tones, but human size power armour and the effectively the equivalent of armoured cavalry – two or four legged – that are not walking tanks, but armoured infantry.

Keeping things down on the small end, there are basically 3 sources of inspiration: You have Shirow's Landmates from Appleseed, VOTOMs, and the Tactical Armors/Fakes from Gasaraki.

A Landmate is controlled by the pilot's motions, it's an overgrown suit of power armor. Civilian versions are used in the heavy-lifting jobs in construction and agriculture. The operator's arms are usually exposed (but armored), and the operator's legs extend into the legs of the Landmate. But this makes for a severe weakness in military terms: you can severely injure the pilot by targeting the hip joint of the Landmate.

A VOTOM or Tactical Armor is piloted, not worn. The pilot is stuffed into the chest of the mecha, completely encased by the armor. Much better protected, to tell you the truth. I'm not sure there's a single pilot kill in Gasaraki, even though several suits get limbs blown off.

What I find the most upsetting in this debate is this.

This is some how acceptable,

While this is not,

I've sorry, but I'm finding Gundams and Mobile suits a bit easier to swallow than AT-ATs.

But AT ATs make sense because they're troop transports! ;)

No, there are a few things you'd need to make mechs viable and a few more that you'd need to make them a better choice than tanks.

The first one is really good point defense lasers to deal with missiles and high velocity projectiles. ECM is all well and good but you need a weapon that fire at a fast enough speed to stop cannon rounds not just seeking missiles. Next you still need some serious ECM. Joints in the armor aren't really the weak point people make them out to be. If they're strong enough to take the stresses being put on them in normal use, you probably won't be too worried about bazookas.

Which brings us to one of the other things, materials that can take the strain without being heavy enough that they just add to the problem. Ground pressure isn't half the issue ankle pressure is. As someone else pointed out proportionally big feet mostly solve the ground pressure problem.

The next thing is aircraft. Much as with Steve Jackson's Ogre, laser towers keeping the skies clear makes the tank and mech king again. Mechs are just walking laser towers.

Of course that requires really good stabilization.

We can do a lot with wheels and tracks, but legs are very versatile if more complex and slower. Long strides increase your joint pressure. But theoretically you could be reasonably fast. Need good software to stay upright in rough terrain though.

A reasonably simple legged drivetrain is needed or the things will just die in the logistics.

The ability to hit top armor on tanks most of the time is good, it's easier to put heavy armor on a smaller frontage. David Pulver, author of GURPS Vehicles, made the argument that top attack capability makes the top armor profile favor mechs over tanks. Though most mechs aren't depicted with armored umbrellas.

Well, that's my list for the moment. I lean towards smaller mechs but that's just gravity talking.