Shield Slam rules in GURPS 4e - problems?

[hal]

Hello Folks,
I'm having a difficult time wrapping my head around the Shield Slam rules as presented in GURPS 4e. I'm only too aware that there are times when my understanding of the rules are faulty, but I am also aware that there are times when my reasoning isn't too far off the mark either.

For example, I decided to try a simple "slam" encounter between two characters I called "The Wimp" and the "Linebacker". Wimp's stats are ST 9, DX 10, HP 9 versus Linebacker's stats of ST 15, DX 12, HP 18.

The situation? The wimp tells the linebacker that if the linebacker fails to knock him down, that the linebacker owes him $15. If the linebacker does knock him down, that the linebacker gets paid $5. If the linebacker himself falls down, then the linebacker owes him $30. The linebacker agrees to the deal thinking that this is going to be a pushover - easy money.

Statistically? The linebacker just took a sucker bet that favors the wimp. Why? Using the GURPS rules as written, and assuming that the linebacker never uses an all out attack of any kind (nor uses the added rules from Martial Arts for a Determined attack), the Wimp will win more money from the line backer in multiple slams than the linebacker will win. How is this possible?

Assume that the distance for the "rush" is 3 yards. The linebacker's damage rolls will be based off of 1d6-1. The wimp's? His will be 1d6-2. Since we're talking about a situation of comparing 1d6 versus the roll of another 1d6, that becomes the classic 2d6 probability distribution problem where there are 36 possible permutations. The modified rolls however, make it more interesting. Possible Die Roll results for the wimp are: 0,0,1,2,3,4. Possible die roll results for the Linebacker are: 0,1,2,3,4,5. Compare them against each other for all possible die rolls, and we get the following results:

8 results where the Linebacker falls
16 results where the wimp falls
10 results where the Wimp must make a DX roll to avoid falling
2 results where no one falls.

Since a DX of 10 has a 50/50 chance of success/failure, half of all results where a DX roll must be made, will result in "Wimp falls" and half will result in "No one falls". Thus, the new results after the dex saving rolls are concluded are:

8 results where the linebacker falls
21 results were the wimp falls
7 results where no one falls.

that essentially breaks down to a 22% the linebacker falls, a 58% chance where the wimp falls, and a 30% chance where no one falls.

This already presumes that the linebacker ALWAYS hits his opponent resulting in a contest of damage. Incidentally? GURPS 4e states that you must do at least 2x damage over your opponent to knock him down. My question is - how do you do 2 times the damage of zero? 2 times zero is zero. Zero times two is still zero.

In any event, there are some issues involved with the Slam rules that make me unhappy, and as GM, unwilling to use the rules as written. They are:

A character who weighs 200 lbs, goes up against a character who weighs 150 lbs, but is wearing 50 lbs worth of padding/armor or what have you. Functionally, they should be reasonably identical in their potential to knock each other down. GURPS does not reflect this.

A character whose skill level of 18 with a shield, does not get to roll against their shield skill when slamming with a shield? What if a quarterstaff armed individual decides to cross check with his stave - he doesn't get to use his stave skill in place of DX or Brawling or Sumo Wrestling?

For me - the rules as written are VERY unsatisfactory, and do not seem to reflect reality all that well. Maybe it is just me - maybe I don't understand the rules as written very well. Or maybe I do. I'm hoping I'm wrong actually. But if I'm not, I'm going to have to either go back to the original 3e rules or create my own ad hoc houserule(s) reflecting the changes I think need to be made.

[Lonewulf]

Originally Posted by hal

A character whose skill level of 18 with a shield, does not get to roll against their shield skill when slamming with a shield? What if a quarterstaff armed individual decides to cross check with his stave - he doesn't get to use his stave skill in place of DX or Brawling or Sumo Wrestling?

Pretty sure you DO roll vs. Staff skill to cross-check with a staff.

Same with a shield. Check pg. 372, under Shield Rush: "Roll against shield skill to hit".

I'm not sure what you mean by 150 lbs. vs. 200 lbs. not being more or less equivalent in being able to knock each other down; their HP aren't exactly going to be off the charts. I'd say that that's a difference between, say, 12 HP and 10-11 HP. Not incredibly different. I also don't think that wearing a huge amount of heavy gear will make you any more stable; by that theory, a man put into Very Heavy encumberance by that backpack on his back would be hard to knock down. ;)

I'd also add that the man in padding is less likely to be damaged by the blow.

Originally Posted by hal

GURPS 4e states that you must do at least 2x damage over your opponent to knock him down. My question is - how do you do 2 times the damage of zero? 2 times zero is zero. Zero times two is still zero.

At this point, it looks like you're just looking for things to complain about. Either that, or this is part of some kind of April Fool's joke.

I'm also not sure what you're complaining about towards the beginning of the thread. I'd say that a Linebacker could use his Sports/Football skill, and use that to hit someone; and he's very likely to knock down the other guy, but it's not a guarantee. That's pretty believable in my opinion.

[Bruno]

Originally Posted by hal

A character whose skill level of 18 with a shield, does not get to roll against their shield skill when slamming with a shield?

You're wrong. You do get to roll against your shield skill when slamming with a shield. Turn the page and read the entry on Shield Rushes.

Originally Posted by hal

What if a quarterstaff armed individual decides to cross check with his stave - he doesn't get to use his stave skill in place of DX or Brawling or Sumo Wrestling?

You are explicitly using the rules from the Basic set only. As such, there ARE NO RULES AT ALL for cross checking with a quarterstaff or halbard or whatever. So complaining that he can't use his Staff skill is a little disingenuous.

For reference, this is covered in Martial Arts, and yes, he can use his Staff skill.

[smurf]

I think you have read the rules wrong.

See 371 for Slam

It is an all out attack or Move and Attack (limited to 9)

Damage is

(HP * xYards move)/100

average guy with 10 moves 3 yards does 30pts down to .3 or 1d-2
The schmuck getting hit uses 10pts or .1 or 1d-3

Attacker v defender

A => D = DX roll
A x2> D = Auto down
D x2> A = Auto Down

Add a shield!

Roll vs Shield Skill (which can be better than DX). And add the Shield's DB to the damage roll!

Therefore a step and shunt with a shield can be made an all out attack.

Based on Shield Skill
+2 damage from AoA
+1 to 3 from DB
one step and bash = 1d-3
Even if the worst die rolled a 1 and you had a medium shield that's a result of 2 (1+4-3)
The schmuck without a shield just standing there is going to give 1d-3. Best result is a 3.

The schmuck takes the damage and the guy with the shield uses the shield's DR!

[hal]

Originally Posted by Bruno

You're wrong. You do get to roll against your shield skill when slamming with a shield. Turn the page and read the entry on Shield Rushes.



You are explicitly using the rules from the Basic set only. As such, there ARE NO RULES AT ALL for cross checking with a quarterstaff or halbard or whatever. So complaining that he can't use his Staff skill is a little disingenuous.

For reference, this is covered in Martial Arts, and yes, he can use his Staff skill.

Correct - I found to my rueful amusement, the rules for shield bashes specifically, on the very next page. Timeline wise - I posted my post, took my kid to a lesson, and while waiting for the lesson to be over, read both the GURPS MARTIAL ARTS book and GURPS CAMPAIGNS book in more detail. I found the shield bash rules invoking the use of the shield skill and thought "Egg on face time". None the less, I found it interesting that the shield bash rules add the DB of the shield as a damage bonus in a shield bash. For an individual who is doing 1d6-3 damage, adding an additionall +2 points of damage is in effect, doubling the average damage done by the "bash" attempt. This makes sense? Not to me.

As for the cross checking rules with the quarterstaff, as compared against the original basic rules, if you could list the page you found that on, I'd appreciate it :)

[roguebfl]

Hal why did you rule out AoA? AoA would be exact what the lineback would do, the wimp is not going attack back and non else is either, and their is money and pride on the line why hold back?

[hal]

Originally Posted by Lonewulf

Pretty sure you DO roll vs. Staff skill to cross-check with a staff.

That would be a Martial Arts rule - and I'd have to find its reference. Help would be appreciated if you know what page it is on.

Originally Posted by Lonewulf

Same with a shield. Check pg. 372, under Shield Rush: "Roll against shield skill to hit".

Yup, Found that reference about 40 minutes after I hit the "Submit" button - my mistake :(

Originally Posted by Lonewulf

I'm not sure what you mean by 150 lbs. vs. 200 lbs. not being more or less equivalent in being able to knock each other down; their HP aren't exactly going to be off the charts. I'd say that that's a difference between, say, 12 HP and 10-11 HP. Not incredibly different. I also don't think that wearing a huge amount of heavy gear will make you any more stable; by that theory, a man put into Very Heavy encumberance by that backpack on his back would be hard to knock down. ;)

If you don't think being hit by someone wearing all that football gear or wearing chain armor is going to feel any different than that same individual wearing only street clothes, you may want to reconsider it. I've got painful recollections that would argue against what you just said above. A 150 lb man running into a person is not the same as a 150 lb man wearing more equipment. In the example I gave, wearing an additional 50 lbs of gear for the 150 lb man will make him on par, as massive as a man who normally weighs 200 lbs. Mass is mass.

Originally Posted by Lonewulf

At this point, it looks like you're just looking for things to complain about. Either that, or this is part of some kind of April Fool's joke.

No joke, and not an issue of someone looking to complain just because I've got nothing better to do. I'm surprised that you would even think that, but hey, that's your thought process.

Originally Posted by Lonewulf

I'm also not sure what you're complaining about towards the beginning of the thread. I'd say that a Linebacker could use his Sports/Football skill, and use that to hit someone; and he's very likely to knock down the other guy, but it's not a guarantee. That's pretty believable in my opinion.

Let me see if I have this straight...

You see no problem with game results that let a 145 lb wimp beat a pro-linebacker one time out of five, be able to stop the pro-linebacker one time out of three, and only be knocked down one time out of 2? That, with a disparity of roughly 135 lbs between the two? That, where the wimp's basic lift is only 1/3rd that of the linebacker's? Clearly we disagree on what is "reasonable" or realistic.

[Rupert]

Originally Posted by hal

You see no problem with game results that let a 145 lb wimp beat a pro-linebacker one time out of five, be able to stop the pro-linebacker one time out of three, and only be knocked down one time out of 2? That, with a disparity of roughly 135 lbs between the two? That, where the wimp's basic lift is only 1/3rd that of the linebacker's? Clearly we disagree on what is "reasonable" or realistic.

A fully prepared wimp vs a pro-linebacker that isn't doing an AOA and didn't take a full move first? Why shouldn't the wimp have a chance? It's not like the rules say how he knocked the guy down, he might have 'cheated'.

[hal]

Originally Posted by roguebfl

Hal why did you rule out AoA? AoA would be exact what the lineback would do, the wimp is not going attack back and non else is either, and their is money and pride on the line why hold back?

In real life, the line backer would have to contend with an opponent whose job was to oppose him. As such, it is highly unlikely, that the normal use of the rushing skill in football would include "all out attack: determined".

If you want? Suggest a "Rules as Written" scenario for the ST 9, DX 10, HP 9 wimp versus the ST 15, DX 12, HP 18 football player.

I suspect that the scenario might play out like this:

Wimp takes his position and chooses the wait manuever.

Pro-Lineback takes his position, and waits for the "hike" command.

Wimp's trigger for his wait is to attempt to bash the linebacker as he enters into his hex. Since his action precludes the Linebacker's - be becomes the new "attacker" in the contest. Does the line backer get his "+2 damage" bonus while the wimp is attacking - or does he have to wait until the wimp's turn is over before he can initiate his own bash, and use his all out attack bonus then?

Me? I thought it was simpler to assume no all out attacks, no waits, and just have the linebacker hit the dude like he would any other football player in a game ;)

[hal]

Originally Posted by Rupert

A fully prepared wimp vs a pro-linebacker that isn't doing an AOA and didn't take a full move first? Why shouldn't the wimp have a chance? It's not like the rules say how he knocked the guy down, he might have 'cheated'.

I've been trying to write a short concise response to this, so here goes yet another attempt (6th so far?)

The problem is, when I calculated the permutations of results, it was based solely upon the rolls of 1d6 (modified) versus the results of the other 1d6 (modified). The reason for this is based on the fact that the bash rules have two aspects to them. The first is that you have to secure a hit the usual GURPS way - that is, roll to hit, roll the defender's to defend, and if the defender fails in the defense, finally, roll the resolution. Once you're at the stage of resolving a successful hit, you are now past the point where judgement/voluntary control comes into play, but now at the resolution of the attempt itself. Cheating by the wimp for example, would require that he use a manuever that was illegal - and manuever is a skill thing. Cheating by the wimp for example, might require that he use a grapple to pull down the face guard of the helmet in an attempt to parry the incoming bash attempt. It would not however, be an issue of cheating if the 280 lb mass hit the 145 lb mass, and suddenly the 280 lb mass rebounds, and falls backwards. It would be an issue where the rules say that something unusual happened - something that in real life, statistically probably doesn't occur.

So - take a look at the permutations involved. Create a chart where on one column, you have 1,1,1,1,1,1,2,2,2,2,2,2,3,3,3,3,3,3,4,4,4,4,4,4,5, 5,5,5,5,5,6,6,6,6,6,6 for the Linebacker's rolls - modify the rolls per the Linebacker's damage rolls, then set up a column with 1,2,3,4,5,6,1,2,3,4,5,6,1,2,3,4,5,6,1,2,3,4,5,6,1, 2,3,4,5,6,1,2,3,4,5,6 and modifiy those results per the wimp's damage rolls.

Compare the resulting opposing rolls with each other to determine, what, by the rules as given in GURPS 4e, is the result of the collision.