Spend MP to change facing - a silly rule?

[Sartris]

You know, so that the XL powered Savannah Master going 23/38 has something to shoot for, hehe.

wait it's not to charge?

[Hellraiser]

Making it go so fast that it clears 1 mapboards per turn is fun.

Using the broken charge rules to with that speed is just total cheese of the worst kind, hehehehe.

Besides,  I like the 24MP Locust for doing that.

[Sabelkatten]

Ignoring air resistance, do the math on where a 38 MP ground unit will return to level 0 altitude after going over a level 1 hill.

All the catgirls will be diving for cover. ;)

[BiggRigg42]

Paying MP for turning helps the game feel more realistic to me.

There is a reason why human sprinters run in a straight line: If you are sprinting, it takes additional force to change directions, thanks to momentum; That additional force could have gone to making you run faster, but it didn't because you used it to turn. In other words, people can't run as fast in a zig-zag as they can in a straight line. Anyone who has done both sprints and agility drills knows this. The MP cost for turning represents the difference in speed between agility drills and sprinting.

As for Alpha Strike, the lack of payment for turning sacrifices granularity and realism for ease of play. This sacrifice can hurt the suspension of disbelief, but it is fun.

[Kovax]

Agreed with BiggRigg42, the cost for a facing change reflects the loss of momentum by changing direction.  I could see allowing ONE facing change either at the start or end of movement (since it's not pre-assumed at the start of the following turn that you're moving or not moving), but a 60 degree change anywhere along the way would slow you down.  It takes a LOT of power to overcome the inertia of 20-100 tons of material traveling at speeds in excess of 50kph, which could have been used to move forward faster.

[Scotty]

Counterpoint: ending up with one of those roads that straddles the angle between two rows of hexes shouldn't take double MP to navigate.

[EDG]

Sorry for the necro, but this is something I've been thinking about recently with my realistic movement ponderings...

Turning a 180 v/s moving forward 90 meters doesn't quite seem to be the same effort when I think about it.

I think in hindsight maybe a more balanced method might have been something like 1 turn side is free, while 1MP allows you to do a full 180.

I think something like this would work. I don't think it should cost anything to rotate one hexside (60°). This is probably more "Advanced Rules" territory, but I think the way I'd do it is:

Standing Still: If a mech is Standing Still it can change to any facing for free (and 0 Heat), but it cannot take any other movement that turn (if it does then it's walking/running). [the existing rule about not being able to turn while standing still is just silly IMO. Of course a mech should be able to rotate its feet around on the spot!].

Walking/Running mechs: Walking/Running mechs may rotate 1 hexside for free - rotating 2 hexsides still require 2 MP, 3 hexsides still requires 3 MP. Any rotation (any number of hexes) must be done before they move forward (or backwards) each hex during their movement, not after they move. Reasoning - it's trivial to rotate 60° at most speeds, and you don't really need to slow down to do so. Changing 120 or 180 degrees is much harder though, as you'd basically have to stop and turn around to do that so it should cost MP. Also, rotating before moving means that you can't cheat and get a free double rotate by doing move+rotate, then rotate+move in the next hex.

Sprinting mechs: Same as walking/running, but if the mech wants to turn 2 or 3 hexsides then the player also must make a Piloting roll to avoid Skidding (regardless of terrain type), with no extra modifier if turning 2 hexes, or +1 modifier if turning 3 hexes/180° (on top of the modifiers for hexes moved per turn).

Maybe even have a another rule for fast moving mechs (spending 9 or more MP?) - they can only turn 1 hexside for every two hexes they move, and also have a chance of skidding if they attempt to turn 2 or 3 hexsides.

[Daryk]

Turn modes for 'mechs?  I'm skeptical...

[EDG]

Turn modes for 'mechs?  I'm skeptical...

Just because a vehicle has legs doesn't mean it can turn on a dime when going at speed - there's such a thing as forward momentum.

[garhkal]

Sorry for the necro, but this is something I've been thinking about recently with my realistic movement ponderings...

I think something like this would work. I don't think it should cost anything to rotate one hexside (60°). This is probably more "Advanced Rules" territory, but I think the way I'd do it is:

Standing Still: If a mech is Standing Still it can change to any facing for free (and 0 Heat), but it cannot take any other movement that turn (if it does then it's walking/running). [the existing rule about not being able to turn while standing still is just silly IMO. Of course a mech should be able to rotate its feet around on the spot!].

Walking/Running mechs: Walking/Running mechs may rotate 1 hexside for free - rotating 2 hexsides still require 2 MP, 3 hexsides still requires 3 MP. Any rotation (any number of hexes) must be done before they move forward (or backwards) each hex during their movement, not after they move. Reasoning - it's trivial to rotate 60° at most speeds, and you don't really need to slow down to do so. Changing 120 or 180 degrees is much harder though, as you'd basically have to stop and turn around to do that so it should cost MP. Also, rotating before moving means that you can't cheat and get a free double rotate by doing move+rotate, then rotate+move in the next hex.

Sprinting mechs: Same as walking/running, but if the mech wants to turn 2 or 3 hexsides then the player also must make a Piloting roll to avoid Skidding (regardless of terrain type), with no extra modifier if turning 2 hexes, or +1 modifier if turning 3 hexes/180° (on top of the modifiers for hexes moved per turn).

Maybe even have a another rule for fast moving mechs (spending 9 or more MP?) - they can only turn 1 hexside for every two hexes they move, and also have a chance of skidding if they attempt to turn 2 or 3 hexsides.

I like that option of a 'free hex' before you start moving, or being able to turn ONE hex only if standing still..  Sort of like how some folk change their footing stance..

[EDG]

I like that option of a 'free hex' before you start moving, or being able to turn ONE hex only if standing still..  Sort of like how some folk change their footing stance..

In 10 seconds a stationary mech could certainly turn in place by 180° (or could turn 120° and torso twist the rest). There's absolutely no good reason to limit that - they'd still count as moving 0 hexes for TMM purposes.

[DevianID]

Bit of a necro, but w/e.  The MP to turn facings is all a product of the 10 second turn limit.  In 1 minute turns, it doesnt make sense at all, and alpha strike for example does away with it.

For a better way to think about this, consider a mechs MP as its turning speed.  An urbanmech has a max turning speed of 18 degrees a second, while a phoenix hawk has a turning speed of 54 degrees/second.  Further, costing MP to turn can also illustrate slowing down as energy is lost.  A 60 degree turn on a phoenix hawk reduces its speed from  27 m/s to 24 m/s.  On an urbanmech its 9 m/s to 6 m/s.  The urbanmech loses 55% of its energy to turn compared to the 21% the phoenix hawk loses, but the phoenix hawk loses 3.4 times more energy over all as its has just a much more powerful, agile frame.

[EDG]

For a better way to think about this, consider a mechs MP as its turning speed.  An urbanmech has a max turning speed of 18 degrees a second, while a phoenix hawk has a turning speed of 54 degrees/second.  Further, costing MP to turn can also illustrate slowing down as energy is lost.  A 60 degree turn on a phoenix hawk reduces its speed from  27 m/s to 24 m/s.  On an urbanmech its 9 m/s to 6 m/s.  The urbanmech loses 55% of its energy to turn compared to the 21% the phoenix hawk loses, but the phoenix hawk loses 3.4 times more energy over all as its has just a much more powerful, agile frame.

How is that a better way to think about it? Sorry but that's just justifying a system that makes no sense whatsoever. These aren't vast lumbering industrial tractors, they're bipedal machines that have a good range of movement and can actually move pretty quickly on the ground. Even an Urbanmech moving at 21.6 kph would be able to turn more than 18 degrees a second (do you even appreciate how miniscule that is? Are you saying it can move its torso much around faster than it can just shift its legs?).

Remember mechs have 10 seconds to do this in a hex that's much larger than they are. They're not suddenly changing their direction like a Tron lightcycle, they're arcing around within that hex to the new direction. They (like us or any other legged creature) would easily be able to turn 60 degrees while moving without losing any of their speed, so that should cost 0 MP. Turning 120 degrees however is pretty much the same effort as turning 180 degrees and for that they would have to stop and plant a leg and spring off it, so that should cost MP.

[VanVelding]

Walking backwards becomes a bizzare[sic] exercise when you don´t have to pay MPs to change facing.

This is it for me. Having retreating units in Alpha Strike spin like they're dervishes is one of the system's few drawbacks. Completely unintuitive and removes one of the game's cost/benefit decisions.

I appreciate that the inability to move east/west is onerous, but that's asking for 12 degrees of movement instead of 6. At that point, you could just do away with hexes and impose a 2" penalty if a unit moves its rear arc out of its path of travel or something.

[DevianID]

The urbanmech is about the exact speed of an abrams off road, and it takes an abrams about 18 seconds to spin around safely.  The urbanmech doing the same is about right.  A lot of the turns your describing sound like torso twists, which mech can do seemingly in almost no time at all.  There is a way to turn faster in a mech... falling and standing.  That can spin you around real quick, but for 'safe' turns once standing the mp cost in 10 seconds is good.

Also note, the video games depict mechs not under throttle as being immobile.  This is not the case.  Mechs, even when spending 0 mp, even when prone, are still moving within the 30 meter hex constantly.  So an 'immobile' standing still turn is not what the game represents when you spend MP to turn.

Also, turning 60 degrees at speed in a short period of time ISNT easy.  Indoor tracks with steeper turns versus outdoor tracks, or flat 400m tracks versus slightly banked tracks make a difference in speed, and a 60 degree turn in 30 meters is sharper of a turn then the tracks humans with little legs run on, so the effect would be much more noticeable for mechs.  There is good reason mechs can slip turning 'just' 60 degrees moving on pavement, that is pretty solid as I understand.  The skid giving extra movement is all wrong and incorrect, but that comes after the skid fall.

Finally, the scale messes up preceptions.  Sure, you, a human, can spin in a circle pretty fast.  But what is your angular velocity?  Its not very much, as our radius is small.  But a mech has a much much wider radius just porpotionaly to a human, then multiplied by the 6 times taller bit.  So a wide person at .2 meters radius spinning 1 time in 1 second is looking at 1.23 m/s speed.  A mech, at human proportion which isnt even close to accurate with the wide bodies/shoulders mechs have, would have a 1.2 meter radius and 7.5 meter speed.  So a mech, turning AS FAST as a human doing a 360 in one second, would be turning at 60 degrees per second.  A more realistic wide mech would be half or a third of that, as mechs are far far wider then humans.  Scale messes with perceptions, and a simple turn for a human is 6x slower for a mech.

This is why a giant godzilla walking slowly seems cumbersome as viewed from a distance, but then you calculate the speed its actually moving and it turns out its actually very very fast.

[EDG]

The urbanmech is about the exact speed of an abrams off road, and it takes an abrams about 18 seconds to spin around safely.  The urbanmech doing the same is about right.

It's not even comparable. The abrams is a 60-70 tank, the urbanmech is a 30 ton biped. All the Urbie needs to do is move its foot and pivot. It can do that in way less than 10 seconds.

Also note, the video games depict mechs not under throttle as being immobile.  This is not the case.  Mechs, even when spending 0 mp, even when prone, are still moving within the 30 meter hex constantly.  So an 'immobile' standing still turn is not what the game represents when you spend MP to turn.

What are they doing, dancing from foot to foot? running in circles? doing star jumps? Nah, they're standing still.

Also, turning 60 degrees at speed in a short period of time ISNT easy.

It is REALLY easy to turn 60 degrees in less than 10 seconds, even when running. People do it all the time, even when not on running tracks. 

Finally, the scale messes up preceptions.  Sure, you, a human, can spin in a circle pretty fast.  But what is your angular velocity?  Its not very much, as our radius is small.  But a mech has a much much wider radius just porpotionaly to a human, then multiplied by the 6 times taller bit.  So a wide person at .2 meters radius spinning 1 time in 1 second is looking at 1.23 m/s speed.  A mech, at human proportion which isnt even close to accurate with the wide bodies/shoulders mechs have, would have a 1.2 meter radius and 7.5 meter speed.  So a mech, turning AS FAST as a human doing a 360 in one second, would be turning at 60 degrees per second.  A more realistic wide mech would be half or a third of that, as mechs are far far wider then humans.  Scale messes with perceptions, and a simple turn for a human is 6x slower for a mech.

Now you have a valid physical point in that mechs are larger than humans. But what kind of "turn" are you talking about? A torso twist would need to be faster, sure, but mechs are designed to turn their torsos quickly. Turning the body by moving the feet doesn't take much effort though. I can turn my body (using my feet) 360° in one second. If you think mechs can run at 50+ kph then they sure can move their legs around in a 30m wide hex in 10 seconds (certainly at least 180° in that time).

This is why a giant godzilla walking slowly seems cumbersome as viewed from a distance, but then you calculate the speed its actually moving and it turns out its actually very very fast.

It's moving at a high speed because it's step size is larger compared to humans. The fact that it takes few steps (which people confuse with "walking slowly") to do that relative to a human is a consequence of that.

[Moonsword]

MODERATOR NOTICE

Given people keep bringing up alternatives, this is being moved to Fan Rules.

[DevianID]

I can turn my body (using my feet) 360° in one second

It's moving at a high speed because it's step size is larger compared to humans. The fact that it takes few steps (which people confuse with "walking slowly") to do that relative to a human is a consequence of that.

You are almost there.  See, you can move your feet in a 360 in 1 second.  But a larger thing has to move its feet in a way that LOOKS slower.  Thus, a big thing turning its feet just as fast as you can, will turn 60 degrees in the same time you turn 360.  Note the big thing is NOT slower, it is moving the same speed.  It just looks slower, because it has to move so much more then you cause it is so much bigger.

If you think mechs can run at 50+ kph then they sure can move their legs around in a 30m wide hex in 10 seconds (certainly at least 180° in that time).

  You are the one that showed that a mech moving 50kph doesnt have its feet on the ground at that speed, as it must be running.  So turning, when your feet arnt even on the ground, isnt easy.  Its crazy impressive that mechs can do it, and Ive shown math in the past that illustrates mech pilots are pulling high G maneuvers all the time like a fighter pilot just in normal operation.  So a mech that can move 4 hexes (50ish kph), or it can move 1 30 meter hex and then turn 3 times for a 1 180, but it cant do a 180 after running its top speed, it must slow down to make that 180 turn.  And that makes sense.  A car with a 10 meter turn radius cant make that 10 meter turn at 50kph either, it has to slow down to make a 180.

[Lycanphoenix]

What about IndustrialMechs which (for whatever reason) have tracks on them? Couldn't they hypothetically use their tracks and legs together for added mobility?

[EDG]

You are almost there.  See, you can move your feet in a 360 in 1 second.  But a larger thing has to move its feet in a way that LOOKS slower.  Thus, a big thing turning its feet just as fast as you can, will turn 60 degrees in the same time you turn 360.  Note the big thing is NOT slower, it is moving the same speed.  It just looks slower, because it has to move so much more then you cause it is so much bigger.

I'm not following your logic here. The aim is to move (for example) 60 degrees in 10 seconds (angular velocity of 6 degrees/second). A human can do that very easily. A mech is more massive and requires more energy to do that, but can still do that easily. Sure, it's bigger but if a point 0.2 metres from its centre rotates 6 degrees in one second then a point 2 metres from its centre (on its surface) would also rotate 6 degrees in one second too.

We're not talking about twisting a torso around (which is trivial), turning in place is just pivoting feet or legs a bit to the left or right and letting the body follow.

You are the one that showed that a mech moving 50kph doesnt have its feet on the ground at that speed, as it must be running.  So turning, when your feet arnt even on the ground, isnt easy.

You do understand that runners turn when their feet touch the ground again, right? :). When you're running your feet aren't constantly in the air, it just means that at some point during the stride cycle, your feet are not on the ground at the same time. When you walk, you are always in contact with the ground. If it was so hard for runners to turn then we wouldn't have 400m races around oval tracks! They turn by shifting the weight on their bodies and pivoting around their feet when they touch the ground during their strides.

Its crazy impressive that mechs can do it, and Ive shown math in the past that illustrates mech pilots are pulling high G maneuvers all the time like a fighter pilot just in normal operation.  So a mech that can move 4 hexes (50ish kph), or it can move 1 30 meter hex and then turn 3 times for a 1 180, but it cant do a 180 after running its top speed, it must slow down to make that 180 turn.  And that makes sense.  A car with a 10 meter turn radius cant make that 10 meter turn at 50kph either, it has to slow down to make a 180.

well in the RAW (rules as written) there's nothing stopping a mech from going at full speed and then spending 3 MP to rotate 180°. The 3 MP spent is the "slowing down and turning around" part I guess, and I don't disagree with that - or with spending 2MP to rotate 120°. I just disagree that there should be any cost for changing direction by only 60°.

[EDG]

What about IndustrialMechs which (for whatever reason) have tracks on them? Couldn't they hypothetically use their tracks and legs together for added mobility?

I think with tracks you can turn just by having the tracks going in different directions?

[DevianID]

I just disagree that there should be any cost for changing direction by only 60°.

So changing any direction imparts force based on radius and velocity.  So a 60 degree turn in a 15 meter radius at battletech speeds is a LOT of energy.  I brought up the olympic track because that is a 60 degree turn in a 45m radius, with people "only" running 10 meters a second, and it's been shown that the curved flat track is slower.  So a mech, moving faster then 10m/s, turning with a THIRD the radius, is getting hit with a crazy amount of force that totally would slow the mech down.

I think the part you miss in the scale is thinking that a turn is only 6 degrees or the radius is across the whole turn in a 90+ meter radius, but it's not.  All turns made in btech have a 15m or less radius.

[Lycanphoenix]

This talk of oval tracks makes me think of the Charger, but wearing a jersey or tracksuit.

[DevianID]

This talk of oval tracks makes me think of the Charger, but wearing a jersey or tracksuit.

That would be amazing as a conversion.  With a banshee for muscle.  I have played a race on the megamek grand prix track, it's quite fun risking the skid on corners or playing it safe, but we usually use faster mechs

[EDG]

So changing any direction imparts force based on radius and velocity.  So a 60 degree turn in a 15 meter radius at battletech speeds is a LOT of energy.  I brought up the olympic track because that is a 60 degree turn in a 45m radius, with people "only" running 10 meters a second, and it's been shown that the curved flat track is slower.

This paper talks about turning while sprinting (not normal walking or running):
https://journals.biologists.com/jeb/article/210/6/971/17323/Limitations-to-maximum-running-speed-on-flat

For an athletics track the radius of the circular parts is about 37m, obviously significantly taller than a human runner, so the reduction in speed isn't going to be significant except in racing (that's way larger than the circles used in that paper).  A mech running around a 15m radius circle would be the equivalent of a human sprinting in a 3 or 4 metre circle in that paper (radius is about twice the height of the runner), and it looks like human sprinters at least would be about 60-66% as fast on a turn like that as they would be if sprinting on a straight. Is that enough to qualify for needing to spend 1 MP to turn at that speed?

So a mech, moving faster then 10m/s, turning with a THIRD the radius, is getting hit with a crazy amount of force that totally would slow the mech down.

The equivalent sprint speed for a mech would be more like 15-20 m/s (Fr~5, or about 5-8 MP). So sure, maybe mechs travelling that fast (or faster) would have to spend 1 MP to move as they slow a bit while they turn 1 hexside, but I don't think mechs moving slower than that would need to.