Thread: BRP Mecha

Originally Posted by Pilous

The Uss Iowa was mainly armed by 9x406mm cannons plus 20x120 mm “small” guns :eek: a direct hit of a single 403 mm gun would be capable of obliterate virtually anything...

Ciao

Dario

120mm is the standard caliber for a Zaku MG, which is one of the least effective weapons in the Universal Century (think of it as a 37mm AT gun in WW2: good against early war armour, useless against late war tanks).

Rick-DOM RPG launchers shoot 360mm HE rockets instead of 280mm. These are supposed to destroy a mecha with one hit.

Which means that one single Universal Century mecha carries weapons as effective as those used by the biggest capital ships built in the 20th Century.

Note: the 120mm ordnance does 1d8 in BRP Mecha, the 360mm rocket does 2d8, and I would rate a 400mm shell from the Iowa as 3d6.

Originally Posted by RosenMcStern

120mm is the standard caliber for a Zaku MG, which is one of the least effective weapons in the Universal Century (think of it as a 37mm AT gun in WW2: good against early war armour, useless against late war tanks).

Rick-DOM RPG launchers shoot 360mm HE rockets instead of 280mm. These are supposed to destroy a mecha with one hit.

Which means that one single Universal Century mecha carries weapons as effective as those used by the biggest capital ships built in the 20th Century.

Note: the 120mm ordnance does 1d8 in BRP Mecha, the 360mm rocket does 2d8, and I would rate a 400mm shell from the Iowa as 3d6.

Not knowing much about mecha ( indeed, nothing would be nearer the mark ) but knowing a little about WW2 naval artillery, I think it's worth pointing out that an HE rocket has little or no armour piercing capability, whereas most naval artillery was designed to fire Semi Armour Piercing (SAP) or Armour Piercing (AP) rounds. I think when dealing with modern weaponry and damage you really need two weapon stats, one for armour piercing and one for damage. Indeed I think someone did exactly that with the Striker/BRP conversion in the downloads section

Originally Posted by Agentorange

Not knowing much about mecha ( indeed, nothing would be nearer the mark ) but knowing a little about WW2 naval artillery, I think it's worth pointing out that an HE rocket has little or no armour piercing capability, whereas most naval artillery was designed to fire Semi Armour Piercing (SAP) or Armour Piercing (AP) rounds. I think when dealing with modern weaponry and damage you really need two weapon stats, one for armour piercing and one for damage. Indeed I think someone did exactly that with the Striker/BRP conversion in the downloads section

Very true. The stats given for Artillery weapons in BRP do not differentiate between HE and AP, not even for the tank guns which usually have at least three types of round available. We might try to provide more detailed rules for this in BRP Mecha, but since most of them will have energy weapons rather than ballistic ones I think we will not go very far with this.

The other thing that occurred to me about the ballistic stuff is ammunition supply. You mentioned a while back that the smallest Mecha in the supplement were about 4.5 metres tall, which is what ? about 14-15 ft tall ? Ammunition supply for the kinetic/ballistic stuff is going to be fairly limited, at least for the large calibre stuff. Granted rail guns and such like weapons don't require shell casings/cartridges etc etc so you could probably get away with a larger capacity there, but rockets or missiles are going to take up a fair bit of space.

AP/HE ROUNDS...
've been working on some rules for different types of ammo for vehicles. I've been trying to get the burst radius for shells to mostly closely match real world data. Unfortunately the "shrapnel" rules in the BRP core book don't work very well, so I has to make some adjustments.

I added a "secondary explosion" effect to some shells to help reflect the fact that some round do indeed have a secondary explosion (like the 406mm AP round), or will cause damage though "spauling" and such.

Perhaps some of this might be useful for mecha. I've been meaning to send Rosen some of my notes for consideration, but have been sick lately.



MECHA AMMO CAPACITY

No doubt that there is some truth to this. Then again a lot of mecha shows give the robots "Hollywood Clips" and "regenerating" missiles. I would suspect this depends on how realtic the setting the GM is running-Mechaseries cover a lot of ground. Perhaps Rosen will make this an optional rule for BRP Mecha?

3D6 400mm gun AND SCALING
Hmm, 3D6 might just work for the vehicle stats, too. Especially if we consider that the penetration for those naval guns dropped off over range, and that MEcha tend to fight much close than battleships did.


The major limiting factore is the AP, SIZ and HP ratings of ships in the core rules. With a battleship having around 36 AP and 480 HP, big gun damages can't be too high or too low without making batteships too vulnerable or too tough.

But that assumes the BB Stats in the core rules are being used. Toss those out and it's a whole different story.

Originally Posted by Atgxtg

AP/HE ROUNDS...

Better avoid these. They have limited impact on mecha combat and make things more complex.

I would suspect this depends on how realtic the setting the GM is running-Mechaseries cover a lot of ground.

Exactly. In some kind of campaigns you have unlimited (or humongous) amounts of missiles. In others you have realistic ammo supplies: 100 rounds per SMG and 4-10 missiles per launcher.

3D6 400mm gun AND SCALING
Hmm, 3D6 might just work for the vehicle stats, too. Especially if we consider that the penetration for those naval guns dropped off over range, and that MEcha tend to fight much close than battleships did.

The major limiting factore is the AP, SIZ and HP ratings of ships in the core rules. With a battleship having around 36 AP and 480 HP, big gun damages can't be too high or too low without making batteships too vulnerable or too tough.

The battleship in the core book would have 4 APs and 48 HPs on mecha scale (not exactly so, as it would have locations/sections with, say, 16 HPs). A 400mm gun doing 3d6 would disable a section with an average of 3 shots. Attacked by, say, Zakus, it would be hit by SMGs doing 1d8 (need a good roll to pass armor) or missiles doing 2d6. Enough to do some damage and disable some systems. Note that a spaceship would possibly have similar statistics. Char Aznable managed to destroy three spaceships in a battle with a Zaku, which is hardly believable given the average damage above, but Char has at least 90% skill, and SMGs can impale, so it can be done.

All in all, the stats for guns and ships are not too "wrong". Of course energy weapons would blast through those armors in seconds. And spaceships have mostly energy weapons and missiles doing 3d6/4d6 at least.

Any chance of some giant mecha who sort of resemble the Shogun Warriors?

I hope that the book has a section covering giant monsters, to give the mecha something to fight other than each other.

Thumbs up for giant monsters and Shogun Warriors!

You may have noticed that I already posted the stats for some of the "Shogun Warriors" (name used only in the US) one year ago. No stats for copyrighted materials will be there, of course, but you will be able to build your own versions. Some of the examples in the chapters I have already written are taken from Shogun Warriors anime.

As for giant monsters, the ones that mechas fight are usually mechanical in nature, more cyborgs than Kaiju. The few exceptions are easy to stat for a clever GM. But I could include some stats for cyborg dinos and haniwa genjins.

Originally Posted by RosenMcStern

Better avoid these. They have limited impact on mecha combat and make things more complex.

Fair enough. IMO they are more of a factor when infantry get involved, anyway. Seems like things look compatible enough between my notes and BRP MEcha that someone could port the rules over themselves anyway, if the desired to.

Exactly. In some kind of campaigns you have unlimited (or humongous) amounts of missiles. In others you have realistic ammo supplies: 100 rounds per SMG and 4-10 missiles per launcher.

Sounds good to me.

The battleship in the core book would have 4 APs and 48 HPs on mecha scale (not exactly so, as it would have locations/sections with, say, 16 HPs). A 400mm gun doing 3d6 would disable a section with an average of 3 shots. Attacked by, say, Zakus, it would be hit by SMGs doing 1d8 (need a good roll to pass armor) or missiles doing 2d6. Enough to do some damage and disable some systems. Note that a spaceship would possibly have similar statistics. Char Aznable managed to destroy three spaceships in a battle with a Zaku, which is hardly believable given the average damage above, but Char has at least 90% skill, and SMGs can impale, so it can be done.

You are letting vehicle weapons get "impales"? That can be somewhat problematic, since it will let some weapons penetrate armor that it probably never could. On man-to-man scale, impales made sense, since there are always gaps in the armor, but can be a problem with vehicles, since AP doen't increase as fast as damage does.

All in all, the stats for guns and ships are not too "wrong". Of course energy weapons would blast through those armors in seconds. And spaceships have mostly energy weapons and missiles doing 3d6/4d6 at least.

No, not too wrong. Another factor worth considering is that mecha weapons are almost always going to be more advanced and more powerful than WWII era weapons. The modern 120mm APFSDSDU used in the M1A2 has penetration capabilities comparable to the 406mm cannon-at least out to about 2km or so. Chances are the 120mm cannon used by mecha are probably ever better that the APFSDSDU, and inflict even more damage. SO there is probably a lot of "wiggle room" for weapon stats.