Rail Guns and Knockdown

[Mack]

In another topic Mark Hall brought up using Knockdown with Rail Guns, which got me to thinking and then running some quick analysis. Since the Knockdown tables on p35 of RGMG are based on damage, I decided to see how effective the traditional SAMAS rail gun and a Boom Gun are at knocking someone down. As expected, those two weapons have significantly different results:

Assuming no bonus to strike:
18% chance of a C-40R knocking down a humanoid target.
63% chance of a Boom Gun knocking down a humanoid target.
--and--
2.3% chance of a C-40R knocking down a supernatural target.
32% chance of a Boom Gun knocking down a supernatural target.

Assuming +3 strike bonus:
22% chance of a C-40R knocking down a humanoid target.
78% chance of a Boom Gun knocking down a humanoid target.
--and--
2.7% chance of a C-40R knocking down a supernatural target.
39% chance of a Boom Gun knocking down a supernatural target.

Then I got to thinking about the Armor Piercing rule, how it would significantly increase the damage of a rail gun. So I re-ran the numbers...

Assuming no bonus to strike, with the AP rule:
23% chance of a C-40R knocking down a humanoid target.
64% chance of a Boom Gun knocking down a humanoid target.
--and--
4.5% chance of a C-40R knocking down a supernatural target.
36% chance of a Boom Gun knocking down a supernatural target.

Assuming +3 strike bonus, with the AP rule:
33% chance of a C-40R knocking down a humanoid target.
78% chance of a Boom Gun knocking down a humanoid target.
--and--
7.1% chance of a C-40R knocking down a supernatural target.
49% chance of a Boom Gun knocking down a supernatural target.


Or in table form...

Code: Select all

                      C-40R    C-40R +3   Boom Gun    Boom Gun +3
Std roll, Humanoid    18%      22%        63%         78%
AP roll, Humanoid     23%      33%        64%         78%
Std roll, Supern’tl   2.3%     2.7%       32%         39%
AP roll, Supern’tl    4.5%     7.1%       36%         49%

So a C-40R has an OK chance of knocking down a humanoid, and a miniscule chance of knocking down a supernatural.
And a Boom Gun has an excellent chance of knocking down a humanoid, and a decent chance of knocking down a supernatural.

[wyrmraker]

I'll admit to not liking the knockdown rules in RGMG. They seem somewhat... lacking, all things considered. If MDC damage is 100x more powerful than SDC damage, then MDC knockdown using kinetic rounds should be staggeringly common.

[eliakon]

In another topic Mark Hall brought up using Knockdown with Rail Guns, which got me to thinking and then running some quick analysis. Since the Knockdown tables on p35 of RGMG are based on damage, I decided to see how effective the traditional SAMAS rail gun and a Boom Gun are at knocking someone down. As expected, those two weapons have significantly different results:

Assuming no bonus to strike:
18% chance of a C-40R knocking down a humanoid target.
63% chance of a Boom Gun knocking down a humanoid target.
--and--
2.3% chance of a C-40R knocking down a supernatural target.
32% chance of a Boom Gun knocking down a supernatural target.

Assuming +3 strike bonus:
22% chance of a C-40R knocking down a humanoid target.
78% chance of a Boom Gun knocking down a humanoid target.
--and--
2.7% chance of a C-40R knocking down a supernatural target.
39% chance of a Boom Gun knocking down a supernatural target.

Then I got to thinking about the Armor Piercing rule, how it would significantly increase the damage of a rail gun. So I re-ran the numbers...

Assuming no bonus to strike, with the AP rule:
23% chance of a C-40R knocking down a humanoid target.
64% chance of a Boom Gun knocking down a humanoid target.
--and--
4.5% chance of a C-40R knocking down a supernatural target.
36% chance of a Boom Gun knocking down a supernatural target.

Assuming +3 strike bonus, with the AP rule:
33% chance of a C-40R knocking down a humanoid target.
78% chance of a Boom Gun knocking down a humanoid target.
--and--
7.1% chance of a C-40R knocking down a supernatural target.
49% chance of a Boom Gun knocking down a supernatural target.


Or in table form...

Code: Select all

                      C-40R    C-40R +3   Boom Gun    Boom Gun +3
Std roll, Humanoid    18%      22%        63%         78%
AP roll, Humanoid     23%      33%        64%         78%
Std roll, Supern’tl   2.3%     2.7%       32%         39%
AP roll, Supern’tl    4.5%     7.1%       36%         49%

So a C-40R has an OK chance of knocking down a humanoid, and a miniscule chance of knocking down a supernatural.
And a Boom Gun has an excellent chance of knocking down a humanoid, and a decent chance of knocking down a supernatural.

I'm not sure that I find that to be a bad thing.
Rail guns should get a bit of a better perk not become an I Win button.
So to me, having a small chance of knockdown is fine. Since Knockdown is pretty harsh
That Boomgun is basically now a death sentence to many targets (which goes along way toward explaining why they are so deadly and feared). Since each time you get shot there is a very good chance that you lose your next action... and any video game player can tell you about the hideous power of the mighty Stun-Lock.

[dragonfett]

That's pretty much what I expected concerning Knockdown and the supernatural.

[ShadowLogan]

RGMG Knockdown rules, how do these compare to the ones in RCB1r (pg14-5)? Or the ones in RUE (pg366) or old Rifts Main Book (pg12) that required a much higher threshold (50 and 30 MD respectively) before they even have to be worried about, and most railguns under these rules under high end roll(s)?

[Mack]

RGMG Knockdown rules, how do these compare to the ones in RCB1r (pg14-5)? Or the ones in RUE (pg366) or old Rifts Main Book (pg12) that required a much higher threshold (50 and 30 MD respectively) before they even have to be worried about, and most railguns under these rules under high end roll(s)?

RGMG rules are exactly the same as the RCB1r rules.
RMB leaves it almost entirely up to the GM, with a generic statement about 30 MD and using common sense.
RUE... I assume you meant p346 and not p366. I don't find any reference to the 50 MD you mentioned.

Effectively the RGMG & RCB1r rules are an optional clarification of the RMBs general statement. They give the GM a possible solution instead of always have to figure it out on their own.

As for the threshold, at 30 MD a rail gun would only have a 30% chance of knocking down a humanoid, and no chance against a supernatural. I don't see where you found the 50 MD reference in RUE, but that would be a 70% chance of knocking down a humanoid, and only a 10% chance of knocking down a supernatural.

[ShadowLogan]

RGMG Knockdown rules, how do these compare to the ones in RCB1r (pg14-5)? Or the ones in RUE (pg366) or old Rifts Main Book (pg12) that required a much higher threshold (50 and 30 MD respectively) before they even have to be worried about, and most railguns under these rules under high end roll(s)?

RGMG rules are exactly the same as the RCB1r rules.
RMB leaves it almost entirely up to the GM, with a generic statement about 30 MD and using common sense.
RUE... I assume you meant p346 and not p366. I don't find any reference to the 50 MD you mentioned.

Effectively the RGMG & RCB1r rules are an optional clarification of the RMBs general statement. They give the GM a possible solution instead of always have to figure it out on their own.

As for the threshold, at 30 MD a rail gun would only have a 30% chance of knocking down a humanoid, and no chance against a supernatural. I don't see where you found the 50 MD reference in RUE, but that would be a 70% chance of knocking down a humanoid, and only a 10% chance of knocking down a supernatural.

Sorry typo for RUE check pg356, its in the paragraph just above the only graphic on the page (below which is "Mega-Damage Technology" bold heading).

I agree they are optional rules and in general.

[glitterboy2098]

Or in table form...

Code: Select all

                      C-40R    C-40R +3   Boom Gun    Boom Gun +3
Std roll, Humanoid    18%      22%        63%         78%
AP roll, Humanoid     23%      33%        64%         78%
Std roll, Supern’tl   2.3%     2.7%       32%         39%
AP roll, Supern’tl    4.5%     7.1%       36%         49%

So a C-40R has an OK chance of knocking down a humanoid, and a miniscule chance of knocking down a supernatural.
And a Boom Gun has an excellent chance of knocking down a humanoid, and a decent chance of knocking down a supernatural.

ok i need to ask.. what is the importance of the +3 strike bonus to the non-AP shots? as far as i am aware, the weapon being more accurate is not going to effect its per shot damage. and it isn't like that bonus applies to the critical.

i can see why it would matter to the AP version, since that could effect what type of crit it gets.


and it looks like my suggestion on the other thread about reducing the damage required on the table for railguns was in error.

[Mack]

Or in table form...

Code: Select all

                      C-40R    C-40R +3   Boom Gun    Boom Gun +3
Std roll, Humanoid    18%      22%        63%         78%
AP roll, Humanoid     23%      33%        64%         78%
Std roll, Supern’tl   2.3%     2.7%       32%         39%
AP roll, Supern’tl    4.5%     7.1%       36%         49%

So a C-40R has an OK chance of knocking down a humanoid, and a miniscule chance of knocking down a supernatural.
And a Boom Gun has an excellent chance of knocking down a humanoid, and a decent chance of knocking down a supernatural.

ok i need to ask.. what is the importance of the +3 strike bonus to the non-AP shots? as far as i am aware, the weapon being more accurate is not going to effect its per shot damage. and it isn't like that bonus applies to the critical.

i can see why it would matter to the AP version, since that could effect what type of crit it gets.

Just means that instead of missing the target (automatically no knockdown) the weapon now hits more often and has additional chances to inflict a knockdown. (A strike roll of 7 is a miss... but with a +3 to strike it's now a hit and might cause knockdown.)

[Mack]

Sorry typo for RUE check pg356, its in the paragraph just above the only graphic on the page (below which is "Mega-Damage Technology" bold heading).

I agree they are optional rules and in general.

Thanks, found it. Looks like a cut-n-paste from RUE with the damage revised from 30 to 50.

[Library Ogre]

Dirt simple knockdown rules: damage inflicted by kinetic weapons (rail guns, high explosive missiles) is % chance of knockdown. Knockdown equals "Lose 1 attack, move to the back of the initiative order." It also includes "need to stand up" or "falling damage" at the GMs discretion.

*2 for Flying
*.5 for more than 600 pounds/275 kilos (started with "more than twice man-sized, but changed it to this; 300# is a big person, or a reasonably sized person with a lot of gear)
*.5 for supernatural or robotic strength
*.5 for four or more contact points with the ground (i.e. wheels, feet, etc.; I count "two treads" in this category, 'cause those are BIG contact points).
*.5 for energy weapons

So, if I shoot a dragon for 40 points of damage with a railgun, there's a base 40% knockdown. If he's on the ground, that gets reduced for Size (40%/2= 20%), Strength (20%/2=10%), and 4 Legs (10%/2=5%)... 5% chance of knockdown. If he's flying, it gets changed by flying (40%*2=80%), Size (80%/2=40%), and Strength (40%/2). If he's changed to look human sized, then he loses the size modifiers.

If I do that same 40 points of damage with a plasma weapon, the base is 20% (40 points of damage, half for an energy weapon)... but since the dragon only takes half damage from plasma weapons, the base is 10% knockdown, further reduced by size, strength, and altered by whether they're flying or not.

It's simple. It gives a clear advantage to kinetic weapons, and explains why they're popular in some circles over their more damaging energy counterparts, but doesn't leave folks with energy weapons wondering why they bothered to show up to the party.

[Axelmania]

Mack do you know where I can find this Armor Piercing rule you are referring to? Kinda lost.

Wondering with explosions.. Damage on these tables... If a Roll With Impact succeeds, based on halved damage?

[Mack]

Mack do you know where I can find this Armor Piercing rule you are referring to? Kinda lost.

In the back of RUE, in the missile section on a left hand page. (Don't have the book in front of me. But the other Rail Gun topic may have the page number.)

[Axelmania]

RUE 362's "Missile Damage Notes" first paragraph "Armor Piercing explosives" ? Only talks about AP Missiles, was there something about applying these to railgun rounds somewhere?

The double on 18-20 mod and triple on nat 20 is a nice advantage for knockdown, hadn't thought of that. I wasn't sure if knockdown was based on base damage or end result damage.

If we apply multipliers for increased knockdown then it might stand to reason to apply divisors for decreased knockdown like a roll with impact.

What about stuff like people who take half damage from fire getting hit with a plasma missile? Not sure if they cause knockdown.

[glitterboy2098]

RUE 362's "Missile Damage Notes" first paragraph "Armor Piercing explosives" ? Only talks about AP Missiles, was there something about applying these to railgun rounds somewhere?

they do not apply RAW. this thread is a spin off of the Houserule me: Railguns thread, where the knockdown rules were mentioned as a way to make railguns more useful, and the idea of using the AP modifiers off the missiles for railguns was proposed as an option to make railguns more powerful.

this was mentioned in the first post, making me wonder how you missed it.

[Axelmania]

It says it was brought up in another topic. Not which topic or that it is a house rule.

[guardiandashi]

It says it was brought up in another topic. Not which topic or that it is a house rule.

It specifically says the other topic /thread was about rail guns and using knock-down to make them a bit more nasty. It then goes on to suggest using the armor piercing rules to see how much that mod would further effect railguns

[Axelmania]

It says it was brought up in another topic. Not which topic or that it is a house rule.

It specifically says the other topic /thread was about rail guns and using knock-down to make them a bit more nasty. It then goes on to suggest using the armor piercing rules to see how much that mod would further effect railguns

Nope, reread OP:

In another topic Mark Hall brought up using Knockdown with Rail Guns
..
I got to thinking about the Armor Piercing rule, how it would significantly increase the damage of a rail gun

Does not say the overall thread was about railguns (or when the thread was, so it could be years old) just that in another topic it was brought up. Suggestion of using a rule is not the same as clarifying it is a house rule. So the inquiry was good.