truly realistic movement rules?

[dataweaver]

I've recently picked up a copy of The Ultimate Vehicle, and was less than impressed by the way that it handled several aspects of vehicle movement - namely, gravity-powered and towed ground vehicles, the effect of wind on aircraft, and the so-called "realistic" rules for space movement. In all three cases, it seemed to me that the writer was trying to shoehorn realistic movement concepts into the existing (and inherently unrealistic) movement rules. This has substantial possibilities for Murphy's Rules, as well as unneccessarily cluttering up the ruleset with additional patches.

 

What I'd like to see would be an alternate set of movement rules that's geared toward a more realistic treatment of the subject, primarily for use in Hard SF games. For instance, wagons, bobsleds, and sidecars wouldn't have a limited form of Gliding; instead, they'd have a specialized version of Environmental Movement common to vehicles: "rolls or slides easily" (1 pt at most), and the rules would include something about using STR to pull wagons or sleds. More importantly, I'd want a realistic treatment of movement in general. Forget applying Ads, Limits, and/or Adders to Movement Powers in order to simulate realistic movement; just change the underlying movement ruleset to one better tuned for realism. It's not like you'd ever want to use both rulesets at the same time...

 

For instance: Equate "combat speed" to acceleration, and "noncombat speed" to Top Speed. Your Turn Mode equals your current speed times whatever multiple of your combat speed you're currently moving at (unless the vehicle has limited maneuverability); your acceleration per inch is based on whatever multiple of your combat speed you're currently moving at. "Normal Space" movement has no Noncombat Multiple, but noncombat speed can go as high as 1.8 billion inches per turn if you have the time and END to manage it (also, "Normal Space" movement only costs END when accelerating, decelerating, or turning, and the cost is based on the change in speed and/or the turning radius; it might work well as a new power akin to Flight).

 

Of course, I'd also revise the jumping and swinging rules; the rules for how far you can jump or swing are fine, but the speed at which you can jump should be based entirely on the local gravity, independent of your inches of Superleap - and swinging should handle both how quickly you can swing and how long your swingline can be (think of the former as being a measure of how much tension the swingline can take before breaking).

 

Finally, "tailwinds" should allow aircraft to exceed their purchased noncombat speed (in inches per turn), and by an amount equal to the windspeed. IMHO, this is in the same category as gravity-powered and towed ground movement, in that all three are "unpowered".

[NuSoardGraphite]

Re: truly realistic movement rules?

 

Originally posted by dataweaver

 

 

 

For instance: Equate "combat speed" to acceleration, and "noncombat speed" to Top Speed. Your Turn Mode equals your current speed times whatever multiple of your combat speed you're currently moving at (unless the vehicle has limited maneuverability); your acceleration per inch is based on whatever multiple of your combat speed you're currently moving at. "Normal Space" movement has no Noncombat Multiple, but noncombat speed can go as high as 1.8 billion inches per turn if you have the time and END to manage it (also, "Normal Space" movement only costs END when accelerating, decelerating, or turning, and the cost is based on the change in speed and/or the turning radius; it might work well as a new power akin to Flight).

 

 

 

Hey!

 

I've been doing flight this way for about 3-4 years now. In fact, I just mentioned this method to someone on another Thread in the Star Hero section. It would only really apply to vehicular movement in a Heroic level game, and would only ever really be an issue in Scifi games.

I recommend this method to anyone who plans on running Star Hero.

[Talon]

Re: truly realistic movement rules?

 

Originally posted by dataweaver

For instance: Equate "combat speed" to acceleration, and "noncombat speed" to Top Speed. Your Turn Mode equals your current speed times whatever multiple of your combat speed you're currently moving at (unless the vehicle has limited maneuverability); your acceleration per inch is based on whatever multiple of your combat speed you're currently moving at. "Normal Space" movement has no Noncombat Multiple, but noncombat speed can go as high as 1.8 billion inches per turn if you have the time and END to manage it (also, "Normal Space" movement only costs END when accelerating, decelerating, or turning, and the cost is based on the change in speed and/or the turning radius; it might work well as a new power akin to Flight).

 

I actually submitted a rule to this effect during Star Hero playtesting, but it didn't make it in.

 

IMO, most of TUV does a good job of compromising between Hero System rules and reality. Creating a thoroughly realistic movement system is beyond the scope of a supplement and would really require another rules revision. You can simulate a lot of the fine detail (tailwinds, towed vehicles, etc.) by simple rules changes or GM fiat if you like.

[Fuzzy Gnome]

Another issue: No banking in space.

If you don't have airfoils (and air), there's no such thing as "turn mode." You can change your vector by whatever amount you like, up to your combat velocity, but no more. There are no 8G fighter plane turns in space, unless you have the power to do the same acceleration on the straightaway.

 

Noncombat velocity maximum depends on the density of the medium. If you have a top NCM of 1000 kph at some defined cruising altitude, it'll be less at ground level and more at a higher altitude. In space there's no limit as Nu Soard already mentioned.

Terminal velocity is the same concept as NCM max. It should be affected by the density of the atmosphere, acceleration of gravity, and the weight and shape of what's falling. Assuming drag is proportional to the square of airspeed, terminal velocity should be double four times gravity or one fourth the density of air. There would be no upper limit in vacuum. Each two levels of Density Increase should double terminal velocity.

[dataweaver]

I beg to differ; Turn Modes are essential for space travel, even of the realistic variety. Mind you, realistic space movement incorporates the effects of Sideways Movement automatically; the vessel doesn't need to be pointing in the direction that it's moving. However, a pilot who wishes to maintain a given speed while changing the direction that the vessel is moving is still going to find himself flying along a circular path with a radius determined by a combination of his acceleration and his speed - just like a Turn Mode.

 

I really do wish that something like this had made it into Star Hero and TUV, in place of the "realistic space travel" section that did make it in - those of us who are interested in Hard SF realism don't want to deal with a compromising "twist the existing rules to fit" system, and - as the above post demonstrates - not all of the ramifications of realistic movement rules are intuitively obvious, so a "house rules" approach is likely to end up with oversights and/or clunky solutions (such as the "No Turn Modes in space" suggestion above, or the lack of a "Sideways Movement in space" suggestion in my original post).

[Ace of Spades]

Reality Check

 

Once upon a time a game company published a book aimed at allowing us to play a Mecha / Anime based game.

 

A whole group of us, all dedicated gamers, half of us with degrees in engineering and math happily purchased this game and went off to work up our campaign.

 

We quickly discovered that the rules were written with the critical eye of someone who wanted as much "realism" as possible in the design of Mecha ships for this -anime- / non realistic game.

 

It took three of us eight full hours, working together, to slog through all the math involved in building a balanced and rules legal fighter.

 

We were bright enough to figure out that while the math was cool to do none of us wanted to invest several hundred hours of work just putting together the vehicles for our game...we shuddered as we looked over the complicated equations required to track fuel consumption and how it gradually impacted vehicle manueverability during combat.

 

Was it realistic? Yes the game felt realistic, very realistic. Was the math cool? Yes. Was the game playable as a game by any stretch of the imagination? Not really. We abandoned that book and I believe that was the last book printed by that fine company that we ever purchased.

 

The bottom line needs to be whether the game is playable, generally balanced, easy to learn, and fun to play and write adventures for.

[dataweaver]

At no point have I disputed that; I've great respect for the idea that playability trumps realism. But don't fall into the trap of thinking that these goals are mutually exclusive. Indeed, most of the suggestions above are geared toward greatly increasing realism while simplifying existing rules; the only ones that don't are the Turn Mode/Acceleration-per-inch rules and the jumping/swinging rules. The former was mentioned as part of an attempt to replace a badly kludged system aimed at fans of realism with a purpose-built (and thus more streamlined) system with the same goal. The latter didn't actually get any alternative rules suggested for it because I'm unsure of how to go about doing it without sacrificing playability.

[Talon]

FWIW, I'm working on an "Orbital Mechanics Hero" article which has the intention of taking Newtonian-style movement (Hohmann transfer orbits, etc.) and putting it into Hero in a manner that's reasonable for GMs to manage during a session.

[Fuzzy Gnome]

Originally posted by dataweaver

I beg to differ; Turn Modes are essential for space travel, even of the realistic variety. Mind you, realistic space movement incorporates the effects of Sideways Movement automatically; the vessel doesn't need to be pointing in the direction that it's moving. However, a pilot who wishes to maintain a given speed while changing the direction that the vessel is moving is still going to find himself flying along a circular path with a radius determined by a combination of his acceleration and his speed - just like a Turn Mode.

 

Yeah, but the problem is that the existing Turn Mode rules lead to much greater accelerations while turning than while going straight. In space where there's no physical basis for a top speed things get even worse, because Turn Mode is linear with velocity but the turning radius of a real vehicle is proportional to the square of velocity. If you're moving at 10,000 m/s you won't be making 2 evenly spaced 60 degree turns in a Phase. Heck, an F-15 that tried that at Mach 2.5 would be pulling some 65 Gs.

You could buy Flight with some Limitation that the Turn Mode is really funky and you have to do a bunch of math every time you want to turn the ship, but that would just make the realistic movement system awkward so you wouldn't want to use it. Better to not call it a Turn Mode at all, and just say that you can accelerate up to your CV in any convenient direction in space.

[Old Man]

The cleanest true-vector-based space movement I've seen came from, I think, Triplanetary? Anyway, your ship had two counters, one that represented the ship and another that represented where the ship would be a turn from now. When it came time to move, you put your ship within (thrust) hexes of the "future" counter, then moved the "future" counter such that it was at the hex that was opposite from the hex where the ship used to be. Fortunately, I don't think facing mattered in that game.

 

However, for purposes of practically all popular SF this movement scheme is lame, because in all he movies and TV shows, ships fly through space as though they were aircraft (Star Furies being the one exception that springs to mind). At some point the whole thing has to be abstracted, and Hero is just not as far down the "gritty and realistic" scale as, frex, GURPS. Which is a good thing.

[Guest Keneton]

Why is acceleration unlimited in space? You can only get up to the speed of the exhaust of your fuel?

 

As one approaches light speed (hard science) his mass increases until at the speed of light the mass is infinite. If you want to play hard science then nothing can accelerate to this rate. . .

 

The idea of a Role Playeing Game is to simulate FUN STUFF! Look at Traveller TNE. It got so complicated that it flopped. . .even without stupid VIRUS. Even so their vector and range band sytems were not superior to Hero. I still like Hero bettern than this.

 

[dataweaver]

Originally posted by Fuzzy Gnome

Yeah, but the problem is that the existing Turn Mode rules lead to much greater accelerations while turning than while going straight.

 

So fix the Turn Mode rules, as I suggested above; bypassing them doesn't solve the problem.

 

You could buy Flight with some Limitation that the Turn Mode is really funky and you have to do a bunch of math every time you want to turn the ship, but that would just make the realistic movement system awkward so you wouldn't want to use it. Better to not call it a Turn Mode at all, and just say that you can accelerate up to your CV in any convenient direction in space.

 

I disagree that you'd need to do a bunch of math every time you want to turn a ship; rather, you'd have to do some fairly simple math at the time you create the ship (take the square root of your combat speed to find out how fast you can go and still have a Turn Mode of 1; take the square root of twice your combat speed to find maximum speed for Turn Mode 2; square root of triple your combat speed for a Turn Mode of 3, and so on). This would be needed to provide realistic turn modes for other environments as well (where you don't always have the luxury of being able to accelerate in any direction you want to), so you might as well use it for normal space movement while you're at it.

 

That said, vector-based movement has its advantages as well; it could be presented as another alternative to the "more realistic Turn Modes and Acceleration" model that I've been talking about. There's room for both, especially since vector-based movement can be summed up in under a paragraph.

[Old Man]

Originally posted by Keneton

As one approaches light speed (hard science) his mass increases until at the speed of light the mass is infinite. If you want to play hard science then nothing can accelerate to this rate. . .

 

Actually that's the relativistic mass, not the actual (invariant) mass. Which is a consequence of being able to increase momentum without being able to increase relative velocity. Otherwise it would be possible to create a black hole simply by accelerating an object sufficiently. Anyway... yeah, we don't need this level of detail in the game.

[dataweaver]

Originally posted by Keneton

Why is acceleration unlimited in space? You can only get up to the speed of the exhaust of your fuel?

 

This is a common fallacy, but it simply isn't true. Ships with fast exhausts are more fuel-efficient than ships with slow exhausts, and can thus go faster given the same amount of fuel; but give any rocket enough fuel, and it will eventually be able to attain any sublight speed of your choosing.

 

As one approaches light speed (hard science) his mass increases until at the speed of light the mass is infinite. If you want to play hard science then nothing can accelerate to this rate. . .

 

Reread my proposal; for normal space movement, noncombat speed is replaced with 1.8 billion inches per turn (IOW, the speed of light). True, I neglected to include the effects on mass of relativistic velocities; but the vast majority of games won't need that.

 

The idea of a Role Playeing Game is to simulate FUN STUFF! Look at Traveller TNE. It got so complicated that it flopped. . .even without stupid VIRUS. Even so their vector and range band sytems were not superior to Hero. I still like Hero bettern than this.

 

IOW, those of us who prefer Hard SF games Just Aren't Getting It.

 

Let me try this again, as I'm apparently still not being understood: I am not trying to replace any core rules in Hero. If you are concerned mainly that the game plays smoothly and are willing to sacrifice believability for that goal, you would simply use the established rules as is; my proposal is not intended for you. My proposal is for those who find the unrealistic aspects of the Hero movement system to be something that's interfering with their enjoyment of the game; as such, it's presented as an alternative to the official rules, not as a replacement of them. Those who aren't interested in them ought not use them.

 

The trick is to come up with more realistic rules without sacrificing playability. Just because other games have thrown playability to the wind in favor of realism in the past doesn't mean that every effort geared toward introducing realism has to do likewise. In short, I don't want to hear about how TNE was so unplayable, or how a certain anime-inspired game overdosed on realism and was thus unplayable (incidently, I suspect that an even bigger flaw in that case was a mismatch between an inherently unrealistic genre and an attempt to provide realistic rules for it). I would welcome commentary on how the proposals put forward in this thread are unplayable, and specifically what makes them so; that would give insight on how to improve things, or possibly convince me that I'm on a fool's errand. It would be useful. Rants about how realism sucks and shouldn't be a goal aren't.

 

Finally, a major reason why I brought this up was that TUV and Star Hero make an attempt at more believable rules of the type that I'm looking for; unfortunately, they both bungle it badly by trying too hard to remain consistent with the (essentially unrealistic) core rules. They're clunky and rather unplayable, and they still don't achieve the believability that I'm looking for. What I've proposed is less clunky, more playable, and more believable as is than the official "realistic space movement" rules are; they only "fail" in that they're different from the core rules. If the Hero System has one flaw, it's that it attempts to force everything completely into its mold, no matter how innappropriate that may be.

[Guest Keneton]

Thanks for the clarification Dataweaver. This is a good thread and I now have more of an understanding ofyour point. Here is mine. . .

 

In the hero sytems we play heroes, meaning regardless of power level it is the people and not the tech that matter. Using the standard speed and movement rules, vehicles (as unrealisteic as this seems) move and act like characters.

 

When the BBB came out I was disappointed that the old Champions vehicle sytem (with ACC/DCC etc.) was discontinued wih this non-segmented sytem we have now. Over time I grew to understand why.

 

By making vehicles interact with chractres, the GM can focus on characters.

 

This aside, I really can't believe that I am a proponent of simplicity here. Genrally being a wargaming mechanics nut I go with complication. Also your proposal is actaully simple to operate, and it does make sense.

 

Regarding my grasp of physics, well I'm a mortgage broker . . nuff said. I do know tht most things would take a heck of a lot of time to accellerate to 1.8 billion hexes per turn, ad worse would then take the same amount of time to decellerate!

 

I am not saying that realism does not have its place, but I always hated that Traveller sytem thing where you accellerated the whole time to halfway then flipped over and decelerated the other half way. It sure doesnt lead to any coold pirate hijinks and space dogfights!

 

Maybe there is too much Star Wars in me, but I like the whole space opera thing too much to go real.

 

Enjoying the thread!