4e Mechanics & Rules Discussion

[Raellus]

Originally Posted by Heffe

With that all said, I don't think there would be any issues asking again about your particular issue - I definitely agree that the system when it comes to explosions is wonky.

Ok. I've posted the question on the FL forum.

Originally Posted by Heffe

We may have talked about it before, but my best example of how explosions are weird in 4e is the 25mm cannon firing HE rounds. The 25mm HE round does 4 dmg with a +2 armor modifier. The plate vest has 2 armor, bringing the total damage mitigation to 4. Even with the blast rating of D, because blast dmg is handled separately to direct damage, it would all be mitigated by the vest as well (it's unclear if the blast damage hit location would be rolled separately from the direct damage hit location).

Yeah, I remember that discussion. I could see the above making sense if we were talking shrapnel from a 25mm HE round. Kevlar body armor should be able to stop most small fragments- that's its main purpose. But you're absolutely right- a direct hit from a 25mm round would almost certainly prove fatal (or in game rules terms, prompt a Critical Hit roll, at the very least) to anyone wearing 90s-era ballistic armor.

Originally Posted by Heffe

In any case, I can't imagine that makes any sense from a real world perspective. You can abstract things, but it just feels off. I do think the FL team should have taken some more time considering how explosions are handled - there's a lot of room for improvement on armor modifiers especially.

Agree 100%. Unless FL publishes errata Explosions rules updates (highly unlikely, given Tomas' stated position on errata in general), I think I'm going to have to house rule this one. I'm going to apply both: Direct Damage = shrapnel; Explosion Damage = blast.

I'm not sure that armor should be effective against blast damage. From what I've read about IED explosions in Iraq and Afghanistan, blast wave/overpressure/concussive effects typically bypass body armor altogether, sometimes even killing without leaving a mark on the victim.

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[Heffe]

Originally Posted by Raellus

Ok. I've posted the question on the FL forum.



Yeah, I remember that discussion. I could see the above making sense if we were talking shrapnel from a 25mm HE round. Kevlar body armor should be able to stop most small fragments- that's its main purpose. But you're absolutely right- a direct hit from a 25mm round would almost certainly prove fatal (or in game rules terms, prompt a Critical Hit roll, at the very least) to anyone wearing 90s-era ballistic armor.



Agree 100%. Unless FL publishes errata Explosions rules updates (highly unlikely, given Tomas' stated position on errata in general), I think I'm going to have to house rule this one. I'm going to apply both: Direct Damage = shrapnel; Explosion Damage = blast.

I'm not sure that armor should be effective against blast damage. From what I've read about IED explosions in Iraq and Afghanistan, blast wave/overpressure/concussive effects typically bypass body armor altogether, sometimes even killing without leaving a mark on the victim.

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That's what I've read as well. Direct fire damage is already pretty lethal in game - I think your house rule would just bring explosions into that same arena. If you make any further changes, can you let us know? I'd be interested in how you find the adjustment.

[Raellus]

New clarification question regarding rolled hits, hit location, cover, and CUF. The scenario is as follows:

Target is in a ditch, only upper body is exposed. PC rolls a hit. Hit location die shows legs. Since the target's legs are behind cover (due to the shot angle, several meters of earth), no damage is done. Is this correct, so far?

Now, since the PC rolled a hit, but no damage was done due to the hit location result and target's cover, does the enemy roll CUF or not?

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[swaghauler]

Originally Posted by Raellus

New clarification question regarding rolled hits, hit location, cover, and CUF. The scenario is as follows:

Target is in a ditch, only upper body is exposed. PC rolls a hit. Hit location die shows legs. Since the target's legs are behind cover (due to the shot angle, several meters of earth), no damage is done. Is this correct, so far?

Now, since the PC rolled a hit, but no damage was done due to the hit location result and target's cover, does the enemy roll CUF or not?

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I would. That bullet struck the ground right in front of that soldier. Alternately, you could add a Difficulty Shift to hit and just roll for exposed locations only.

[Heffe]

Originally Posted by Raellus

New clarification question regarding rolled hits, hit location, cover, and CUF. The scenario is as follows:

Target is in a ditch, only upper body is exposed. PC rolls a hit. Hit location die shows legs. Since the target's legs are behind cover (due to the shot angle, several meters of earth), no damage is done. Is this correct, so far?

Now, since the PC rolled a hit, but no damage was done due to the hit location result and target's cover, does the enemy roll CUF or not?

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They would, yes. From the Player Manual pg 67:

"If you are hit by enemy fire (even if the damage is fully deflected by armor or cover), or if one or more ammo dice in a failed attack against you show, you must immediately make a coolness under fire roll."

In this instance, it wasn't just that the ground causes no damage to be done. Rather, the ground itself is counted as a type of "cover", and would thus impart additional points of armor to the PC. Sandbags seem like somewhat of an equivalent, so I'd think the ground would reduce the amount of damage taken for the hit by at least 4 points (probably a lot more, given that the ground is thicker than sandbags and the angle of attack). As a result, no damage actually penetrates the armor/cover to the player, but it does still count as a hit, and therefore CUF would still need to be rolled.

[kcdusk]

Agreed, I'd roll for CUF.

[Raellus]

Originally Posted by Heffe

That's what I've read as well. Direct fire damage is already pretty lethal in game - I think your house rule would just bring explosions into that same arena. If you make any further changes, can you let us know? I'd be interested in how you find the adjustment.

After some discussion, and a helpful video link, over on the FL 4e forum, I've reconciled to the fact that, IRL, 40mm HE rounds are less deadly than I thought they were. As a result, I think I'm going to accept the 4e M203/explosion/HW rules as written, and just take the -2 to aim for individual [human] targets. That way, on a hit, the target takes at least the M203 damage, before even rolling for Blast D damage. Anyone else in the same hex will roll for Blast D damage only.

I think my only house rules re explosions (so far) will be that for a prone target, I drop only one D6, and for a prone target in an enclosed space, like a bedroom for example, I roll both D6 to account for overpressure.

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[Heffe]

Originally Posted by Raellus

After some discussion, and a helpful video link, over on the FL 4e forum, I've reconciled to the fact that, IRL, 40mm HE rounds are less deadly than I thought they were. As a result, I think I'm going to accept the 4e M203/explosion/HW rules as written, and just take the -2 to aim for individual [human] targets. That way, on a hit, the target takes at least the M203 damage, before even rolling for Blast D damage. Anyone else in the same hex will roll for Blast D damage only.

I think my only house rules re explosions (so far) will be that for a prone target, I drop only one D6, and for a prone target in an enclosed space, like a bedroom for example, I roll both D6 to account for overpressure.

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I just watched that same video a few mins ago, and I think your approach is probably the best way to do it.

One thing that I learned from watching the video was that the fragmentation from the 40mm HEDP seemed to have focused downrange from the shooter in a bit of a cone. There was a bit of fragmentation back toward the shooter as well, but the bulk seemed to follow the path of the grenade itself. I don't know why, but in my head I always imagined those types of explosions having the fragmentation spread out in more of a sphere rather than having so much of the blast focused in one direction like that.

[Raellus]

Originally Posted by Heffe

One thing that I learned from watching the video was that the fragmentation from the 40mm HEDP seemed to have focused downrange from the shooter in a bit of a cone. There was a bit of fragmentation back toward the shooter as well, but the bulk seemed to follow the path of the grenade itself. I don't know why, but in my head I always imagined those types of explosions having the fragmentation spread out in more of a sphere rather than having so much of the blast focused in one direction like that.

I think that might be due to the HEDP round's shaped-charge warhead, which should, in theory, focus most of the blast towards the nose/impact fuse of the grenade. HEDP is designed to defeat light armor. I suspect, but have yet to find a source to confirm or refute, that a "vanilla" HE round would produce slightly more blast/shrapnel, and that said would disperse a little more evenly, compared to HEDP.

Would anyone with RL 40mm grenade experience please weigh in?

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[Raellus]

Next questions:

GROUP AMBUSHES: Ambushes can be carried out by a
group and against a group of targets. This follows the
usual rules for stealth – the person with the lowest
RECON skill level rolls for the attackers, while the target
with highest RECON skill level rolls for the targets. If you
succeed, you get all of the top initiative cards, equal to
the number of fighters on your side – i.e. if there are
four attackers, you get cards #1 to #4. You can distribute
these as you see fit. The target(s) draws initiative from
amongst the remaining cards.

WAYLAYING: If you lie in wait for an enemy to attack them
as they pass, roll RECON to set up the ambush. This is a slow
action. If you spend a stretch (5–10 minutes) or more to
set up, you get a +2 modifier. If you spend a shift or more,
you get +3. You can push the roll as normal. Record the
number of you roll.

For Group Ambushes, the rules are clear that you use the lowest Recon score among the attackers. Does this mean that if a party member doesn't have any skill in Recon, you role their Attribute only? Or, does it mean to use the lowest score from among PCs that actually have any Recon skill at all? In other words, what does "lowest" mean? None, or lowest actually score (eg. Recon D)? I'm guessing, it's the former, but hoping it's the latter.

Second, in the Waylaying rules, does the following still apply? "The person with the lowest RECON skill level rolls for the attackers." The Waylaying rule follows the Ambushing rules, but doesn't refer directly back to them, so It's not clear. Post hoc, ergo propter hoc?

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[Tegyrius]

I would interpret it as the same in both cases. Your least-stealthy team member is the gating factor. If that's the dude with AGL D and no Recon, well... better hope you brought overwhelming force in lieu of overwhelming surprise.

(Also, I would consider waylaying a subset or special case of ambushing for rules purposes because the "Waylaying" header is a third-level header under the second-level "Ambush" header - i.e., subordinate in layout/design terms.)

- C.

[swaghauler]

Originally Posted by Raellus

Ok. I've posted the question on the FL forum.



Yeah, I remember that discussion. I could see the above making sense if we were talking shrapnel from a 25mm HE round. Kevlar body armor should be able to stop most small fragments- that's its main purpose. But you're absolutely right- a direct hit from a 25mm round would almost certainly prove fatal (or in game rules terms, prompt a Critical Hit roll, at the very least) to anyone wearing 90s-era ballistic armor.



Agree 100%. Unless FL publishes errata Explosions rules updates (highly unlikely, given Tomas' stated position on errata in general), I think I'm going to have to house rule this one. I'm going to apply both: Direct Damage = shrapnel; Explosion Damage = blast.

I'm not sure that armor should be effective against blast damage. From what I've read about IED explosions in Iraq and Afghanistan, blast wave/overpressure/concussive effects typically bypass body armor altogether, sometimes even killing without leaving a mark on the victim.

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Your assessment of Overpressure Blast damage is reasonably accurate. I say reasonably because sometimes armor does help. M1 Abrams Tanks would INTENTIONALLY roll over small IEDs in Iraq and suffer no real damage from the blast. Alternately, in WWII, the Japanese survived 14" & 16" gun barrages in their bunkers without injury. However, an AH-1 Cobra in Vietnam suppressed an NVA IFV in a rice paddy with 2.75" Rockets. The vehicle was basically only cosmetically damaged but all the occupants were found dead inside from the overpressure blast of the rockets.
I would say VEHICLE armor should be rated at a reduced level for Blast effects damage. Body armor would be worthless from blast damage.

[Raellus]

Originally Posted by swaghauler

I would say VEHICLE armor should be rated at a reduced level for Blast effects damage. Body armor would be worthless from blast damage.

Good point. That's what I meant, but I should have been more clear.

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