Do stop thrusts end movement?

[hal]

Gotta wonder...

If a character is knocked back, if the moving character pays the cost in movement allowance, for moving backwards. The example above brings to mind the following murphy's rules mind image:

"Like a wind up toy, an attacker knocked back slides frictionlessly back exactly 36 inches, and regains full traction to finish its movement before it runs out of it's turns wound up movement. At the start of the attacker's next turn, he is wound up again so he move his full allowance"

Frankly, in my games, being forced back with a knock back while moving forwards results in a backward movement cost plus forward movement costs to resume forward movement. After seeing this thread, I'm likely going to require a SECOND DX saving roll at double encumbrance penalty to resume forward motion in the same turn. You can't easily go forward, backwards, and forwards in the span of under a second without some serious potential balance issues.

[Tomsdad]

I think the reality is unless your being hit by something a lot bigger/stronger than you it is unlikely that if your charging full tilt upon receiving a knock back result your forward force/momentum is not only cancelled but over come in the other direction moving you backwards.


The knock back rules have some assumptions* built in that (IMO) don't mesh well with the recipient charging full tilt in one direction




I'd likely just keep the DX roll to see if charging attacker kept his footing if you hit him with a sw attack for enough damage to normally do knock-back (maybe with a penalty to a balance it up and take into account the rapid foot movement). That way you'll avoid the ping pong ball effect you describe

Although another to avoid it is to take it as overall net result of distance moved, not actually moving forward, backward and forward again, (and don't worry about reach issues)


*I tend to view it being in effect more about unbalanced involuntarily reaction to the hit and needed a bit of space to maintain your footing, rather than the targets entire mass being directly moved by the force of the weapon blow

[aesir23]

Originally Posted by hal

Gotta wonder...

If a character is knocked back, if the moving character pays the cost in movement allowance, for moving backwards. The example above brings to mind the following murphy's rules mind image:

"Like a wind up toy, an attacker knocked back slides frictionlessly back exactly 36 inches, and regains full traction to finish its movement before it runs out of it's turns wound up movement. At the start of the attacker's next turn, he is wound up again so he move his full allowance".

Knock back in GURPS generally makes much more sense if you picture it as "opponent had to take a step backwards or lose their balance" rather than "opponent flies back entirely from the force of the blow."

Part of the problem is it would take much more energy to knock back an opponent who's moving forward than one who's standing still (you have to overcome their forward momentum rather than just tipping their balance back.)

It would make sense to me to say that each hex of knockback merely cancels out one movement point, except that GURPS doesn't alway distinguish between the states "opponent moved last turn but has stopped on his current hex" and "opponent is still moving, but he doesn't have any more movement points to spend until his next turn.

Another problem is Newton's Third Law. If a man is charging me, and I thrust my quarterstaff into him, I may be able to stop him, but I'm also going to be forced backwards.

The only solution I can think of to realistically deal with most of these problems is to come up with some house rules based on Slams.

[Skarg]

I think there's a realism issue with the collapse between 8 points of damage and knockback/knockdown. Even if you say the attack is not trying to damage (say using a padded weapon) and only does half-injury, it is quite possible to hit someone and knock them back or over without doing serious injury the way 8 or even 4 points of injury counts towards unconsciousness & bleeding.

Seems to me that just getting attacked, defending (& of course Retreating), and taking damage would realistically be increasing significant levels of interruption compared to how someone can move when those things are not happening. Currently none of them (except Retreating) have any effect on movement. Taking 8+ points and being knocked off course would I think tend to pretty well mess up someone's movement, more than just 1-3 movement points.

The thing about a Stop Thrust is that it means someone's trying to stop you by putting a pole between you. If they're not failing a skill/DX roll, then they're going to be bracing their feet and keeping it between you. Movement Points and even laws of physics aren't going to get the attacker closer to a successful stop-thruster unless the pole breaks or stops being between the two bodies.

[mlangsdorf]

I'd say if you hit a charger with enough damage to knock him back but he stays on his feet and keeps coming, you didn't knock him back: that was just an abstraction in game terms. What really happened was your hit slowed him a bit but he kept coming. That's easy enough to abstract.

As for a stop hitt always stopping a charger, I don't agree with that. You could hit with a glancing blow that slips off to the side as he moves forward or something like that. Especially if you're using a non-impaling weapon. With an impaling, thrusting weapon, the mechanics are clear that your opponents is impaling himself on your point in order to close the different, and if he's not strong enough or strong-willed enough, he will stop.

[chandley]

Originally Posted by Skarg

The thing about a Stop Thrust is that it means someone's trying to stop you by putting a pole between you. If they're not failing a skill/DX roll, then they're going to be bracing their feet and keeping it between you. Movement Points and even laws of physics aren't going to get the attacker closer to a successful stop-thruster unless the pole breaks or stops being between the two bodies.

The ST check in the oft quoted rules section in Martial Arts p. 106 "Holding a Foe at Bay" represents exactly your effort at keeping your weapon between you and your foe.

[hal]

Originally Posted by mlangsdorf

I'd say if you hit a charger with enough damage to knock him back but he stays on his feet and keeps coming, you didn't knock him back: that was just an abstraction in game terms. What really happened was your hit slowed him a bit but he kept coming. That's easy enough to abstract.

As for a stop hitt always stopping a charger, I don't agree with that. You could hit with a glancing blow that slips off to the side as he moves forward or something like that. Especially if you're using a non-impaling weapon. With an impaling, thrusting weapon, the mechanics are clear that your opponents is impaling himself on your point in order to close the different, and if he's not strong enough or strong-willed enough, he will stop.

A glancing blow would in GURPS terminology, be represented with low damage that doesn't penetrate the armor. In other words, if the damage isn't sufficiently high enough to cause a knockback, it automatically would be deemed (relatively speaking) a glancing blow.

There are issues with the rules as written - rules as written that fail to represent the actual physical events in question. When a GM finds such rules, it is the pleasure of said GM to use his own ruling in lieu of the written rules (ergo House Rule). For instance? A character who started from a standing stop, decides to run as fast as he can in a Northerly direction. On the next round of activity, the player has his character run full out in the same direction - gaining a sprint bonus. So, turn 1, he runs forward 3 yards. Turn 2, he runs forward 4 yards.

Now for the oddity: If at the end of 2 seconds running, the runner is within 1 yard of a potential opponent, how FAST is he moving when he pulls adjacent to the waiting foe? Is he moving 1 (One) hex, or is his speed(velocity) actually still 4 yards per second after moving his first hex forward? He had to be moving FULL speed in a particular direction to gain the sprint bonus last turn, and he has to run the same direction at full speed to gain the sprint bonus THIS turn. So is he moving a speed of 4 towards his foe, or 1?

Me? I treat it as Four - others would say RAW say 1. I say it doesn't make SENSE, ergo tossing the rule out in favor of what I believe SHOULD have been there. <shrug>.

Likewise? Being forced involuntarily to move backwards causes one to be off balance. A knockback, whether it forces the person to fall or not, can force someone off a parapet atop a wall if the blow was in the proper direction to force someone off the wall. So, does the person who is about to be knocked off a wall to be given a DX saving roll to avoid having to step on thin air due to knockback, or would he be granted a DX saving roll to grab at the edge of the wall to avoid falling all the way down because he was forced to step onto thin air?

In all, go with what you feel is right or go with what you feel the rules as written because you feel they are right. It is no skin off my nose whether or you do don't. Any more than it would be skin off your nose if I am hard liner enough to use the house rule with my group that stepping back involuntarily is the same as voluntarily stepping back - costing 2 movement allowance points.

For what it is worth, I've participated in fencing (strip fencing to be precise) and watched people who attempt to lunge forward and return lightning quick backwards) and fallen over because they were either overextended in their lunge, or because they were so off balance when they entered into the lunge to begin with, that they pushed themselves further off-balance when they got too cute trying to move forward and back within the span of less than 1 second. People who engage in any combat will tell you that trying to attack while off balance is a bad idea, and that one is never always entirely perfectly planted to attack with your weapon when any free ranging motion of movement is permitted (ie not restricted like strip fencing is). I've engaged in pit fencing with Adam Crown's group at the New York "Sterling Renaissance Festival" with real weight Spanish grip rapiers. In no less than two occasions that day, I witnessed people falling down (including Adam Crown himself - the fencing master) while engaging in a fast forward lunge and retreat. Yes, the ground was sawdust filled - not muddy, dry, not wet, etc. It wasn't particularly uneven - but the sawdust may have made the ground a wee bit tricky. Problem is? I didn't fall down, nor did anyone from Les Amis Fencing club when we participated in the fun.

In all? Moving Rapidly back and forward is inherently off-balancing, but moving forwards, then backwards, and then forwards in the span of 1 second is going to be even more off-balancing than simply forward and backwards.

Call it as you see it and that's all anyone can do.

[Tomsdad]

Originally Posted by aesir23

...

Knock back in GURPS generally makes much more sense if you picture it as "opponent had to take a step backwards or lose their balance" rather than "opponent flies back entirely from the force of the blow."

Part of the problem is it would take much more energy to knock back an opponent who's moving forward than one who's standing still (you have to overcome their forward momentum rather than just tipping their balance back.)

Yep exactly

Originally Posted by aesir23

It would make sense to me to say that each hex of knockback merely cancels out one movement point, except that GURPS doesn't alway distinguish between the states "opponent moved last turn but has stopped on his current hex" and "opponent is still moving, but he doesn't have any more movement points to spend until his next turn.

Yep, I think you can fudge it somewhat though

Originally Posted by aesir23

Another problem is Newton's Third Law. If a man is charging me, and I thrust my quarterstaff into him, I may be able to stop him, but I'm also going to be forced backwards.
...

Thing is Newtons Third law in abstract doesn't take into account friction, footing and likely braced weapons. i.e the situation is not just two frictionless objects colliding (but yes it will apply at some point if the forces are great enough to overcome all that, as you say above it how you view knock back that's the key)

[Myrion]

Thanks for the discussion, everyone! Now I can definitely both visualize it and understand much better how it works. :)

[hal]

Originally Posted by Tomsdad

Yep exactly




Yep, I think you can fudge it somewhat though



Thing is Newtons Third law in abstract doesn't take into account friction, footing and likely braced weapons. i.e the situation is not just two frictionless objects colliding (but yes it will apply at some point if the forces are great enough to overcome all that, as you say above it how you view knock back that's the key)

Another possibility to consider is center of gravity when it comes to knock back. Hitting the target below the center of gravity or above it will produce different results against the center. Hitting above the center while a target is running full out would be like clothes lining someone. Hitting nearer to the knees would more than likely cause a stumble effect - all without having inflicting ST-2 damage.