High-speed turning radius

[FeiLin]

So, if I have an ordinary human (BM 5) and a flier (say a dragon, AM 12, enhanced move 1/2), they use the same formula on for high-speed movement, regardless if it's on the ground or in the air, right?

That means, that at move 5 and 12, respectively, the turning radius is 1 since you can only enter the front three hexes normally (so the human could move 300˚ in a circle equivalent to the reach of reach 1 weapon around the combatant's hex, almost completing a lap in a turn, whereas the dragon could complete two). When moving beyond that (6 and 13 respectively), the human has a (realistic) turning radius of 4 (I guess, rounding 3.6 up), whereas the dragon has 17.

I know the speeds are quite high so that makes sense, but I don't like that "jump" between 12 and 13 hexes for the dragon making such a huge impact. I'd prefer a smoother yet realistic transition from normal to high-speed, but I don't know exactly how to fix it. It's nice to have one simple formula, but I've been experimenting with adding SM to the minimum radius (even at low speeds) and subtracting the calculation for the last figure of normal movement from higher speeds, to avoid that jump (for instance, a dragon of SM 2 would have radius 3 up to move 12 and then 5, 8, 11 for move 13, 14, 15, etc. But I'm not quite happy with the balance of complexity vs realism of all this, especially something that would work equally well for my human as for dragons (and preferably also for car chases or spaceships, but that's a wish).

Does anyone have any advice (or could point out what I've missed)?

[Stormcrow]

A human with Basic Speed 5, Basic Move 5 running in a circle at 5 yards/turn has a cinematic turning radius of ⌊5/5⌋ = 1 yard or a realistic turning radius of ⌊5×5/10⌋ = 2 yards. If the human were to improve Basic Move to 6 and run in a circle at 6 yards/turn, they would have a cinematic turning radius of ⌊6/6⌋ = 1 yard or a realistic turning radius of ⌊6×6/10⌋ = 3 yards.

A dragon with Basic Speed 6, Basic Move 6, and Flight flying in a circle at 12 yards/turn has a cinematic turning radius of ⌊12/6⌋ = 2 yards or a realistic turning radius of ⌊12×12/10⌋ = 14 yards. If the dragon were to improve Air Move to 13 and fly in a circle at 13 yards/turn, the cinematic turning radius would be ⌊13/6⌋ = 2 yards and the realistic turning radius would be ⌊13×13/10⌋ = 16 yards.

[FeiLin]

Right, the cinematic rules round down, so that makes sense to do for realistic as well. And I understood it as turning radius only applies for high-speed, but I guess it might make sense at lower speeds as well.

Yeah, I still might rule that SM is still the minimum turning radius (except for move 1, for when you might wanna position a mount for a parade or such).

Another thing that seems a bit annoying is that I'd have to keep track of not only the current speed, but also the distance travelled in a line between turns. Anyone has any advice for reducing book-keeping (while keepin' it real...istic)? I guess a couple of different colored d10/d20 per figure might help.

The reason I'm concerned with this is that I envision aerial/high-speed combat as a bit of a mini-game, that sort of switches into high-paced action, akin to a miniatures game, while not breaking the theme or rules of gurps (too much).

[evileeyore]

Originally Posted by FeiLin

Right, the cinematic rules round down, so that makes sense to do for realistic as well.

Those are the "Realistic Rules". As much as most rules in GURPS are 'realistic'.

And I understood it as turning radius only applies for high-speed, but I guess it might make sense at lower speeds as well.

It does only apply at high speed, that is Sprinting or using Increased Move. If you're getting anything other than 1 turning radius before Velocity has doubled Base Move, you're doing something wrong.

Divide Velocity* by Basic Move, round down. That's how many yards you must move straight forward before executing a single hex facing turn.


This means a human (Move 5) and a Dragon (Move 6) both have a 'tight' sprinting turn radius (everything does), but when the dragon lifts off into the air, it's turn radius changes if it moves at full speed. If the Dragon has to make some tight turns in flight, have it slow down.


* Not a capitalized term of art in GURPS, but the word is used everywhere that they mean "current speed".

Another thing that seems a bit annoying is that I'd have to keep track of not only the current speed, but also the distance travelled in a line between turns. Anyone has any advice for reducing book-keeping (while keepin' it real...istic)? I guess a couple of different colored d10/d20 per figure might help.

In the case of the dragon... it moves two and turns, I'm not seeing the difficulty? Unless you're plotting a long windy course? I just move it two, turn, move however many, turn, etc.

The reason I'm concerned with this is that I envision aerial/high-speed combat as a bit of a mini-game, that sort of switches into high-paced action, akin to a miniatures game, while not breaking the theme or rules of gurps (too much).

Those are best played as not Tactical events, but as Narrative affairs. Also, it's easier on the GM.