On using grenades

[Kaspar]

Trying to get a handle on these things.

Turn 1: Ready maneuver with one hand to take the grande from webbing, or use Fast Draw (Ammo) for an instant draw. Would the Off-hand penalty apply here if using the left hand?

Turn 2: Ready with two hands to pull the pin. The four second fuse starts counting. Would be more convenient if this could be done one-handed, but I guess in real life they decided that would make grenades too unsafe? Still in sci-fi you sometimes see grenades that can be triggered with a thumb press and thrown lefthanded. If working two handed, the main weapon should be in a sling, so that it can be picked up with a single Ready afterwards.

Turn 3: Throw the grenade. Max distance for ST10 is 35m. Extra Effort could be used to boost ST to 11 by spending 1 FP and rolling Will-2 (But I would probably remove the Will roll since Extra Effort in Combat does not require rolling, and Will-2 is a bit too punishing for a simple -crunches numbers- wait, just +3m distance? Forget it).

Throwing skill defaults to DX-3, or just DX if you are only targeting a hex. Page 414 mentions +4 bonus for targeting ‘area of ground with an area-effect or explosive attack’, but for grenades it would only apply when ’lobbed it in a high arc’ (meaning less throwing distance?). But I could give the +4 for mud and other surfaces that the grenade cant bounce off and roll away from.

And incidentally, 1 lb thrown object can deal 1d-4 cr damage if it hits directly. Typical speeds of thrown objects would seem to be about ~20m/s so the grenade would usually take a full second in flight. Fuse 3 seconds.

Turn 4: Grenade hits the ground. Margin of failure for the throwing roll determines scatter distance. Fuse 2 seconds.

Turn 5: Fuse 1 second. Does it explode now or next turn?

Turn 6: Explosion. Individual damage rolls for each character in the blast, divided by Distance*3. But what about a character in the same hex (Distance 0), but not ‘struck directly’? Page 415 mentions ’Contact Explosions’ that ‘deal max possible damage’, so maybe just roll damage dice without any division when standing in the same hex?

Fragmentation damage- attacks with ‘Skill’ 15 and ‘Recoil’ 3 for purposes of extra hits.
“A hit is automatic if the explosive attack actually strikes the target.” Ok, but what about additional hits here? Do I still roll for those?

A TL8 Stun Grenade inflicts HT-5 aff (10 yd.) against stun. But there does not seem to be any rules for regular explosions causing stun (aside from a possibility of a major wound) or deafening people.

And since explosions are ‘large area injury’ we won't see any limb crippling unless only a single limb was exposed to being with.


Throwing the grenade back: The enemy could start reacting on turn 3 (or turn 4 if we account for projectile flight time). By default it is 1 turn to kneel, 1 turn to pick up the grenade (could Fast Draw help here?), 1 turn to throw it away. NOT enough time if reacting on turn four. Or if the thrower aimed for an extra second, ‘cooking off’ the grenade.

Also I wonder how likely it is for modern grenade fuses to be off by a second or two. Or WW2 grenades, or WW1. Probably less reliability as you go back.

I’m thinking of making characters succeed a Perc roll to notice the grenade, and a DX roll to kneel and grab it in a single turn.

[johndallman]

Originally Posted by Kaspar

Turn 2: Ready with two hands to pull the pin. The four second fuse starts counting.

High-Tech, p. 190, has the description of using grenades. It is possible to hold the arming handle down while gripping the grenade, so that the fuse timing does not start until it is thrown.

Originally Posted by Kaspar

Turn 6: Explosion. Individual damage rolls for each character in the blast, divided by Distance*3. But what about a character in the same hex (Distance 0), but not ‘struck directly’? Page 415 mentions ’Contact Explosions’ that ‘deal max possible damage’, so maybe just roll damage dice without any division when standing in the same hex?

Yes, that's what you do.

Originally Posted by Kaspar

Fragmentation damage- attacks with ‘Skill’ 15 and ‘Recoil’ 3 for purposes of extra hits.
“A hit is automatic if the explosive attack actually strikes the target.” Ok, but what about additional hits here? Do I still roll for those?

Yes, roll the "attack" to get the number of extra hits.

Originally Posted by Kaspar

Also I wonder how likely it is for modern grenade fuses to be off by a second or two. Or WW2 grenades, or WW1. Probably less reliability as you go back.

Yup, less reliability. TL8 grenades should be accurate; TL6 ones might be off by a second.

Standing in the open drawing and throwing grenades is suicidal if there are enemy riflemen around: you need cover both for concealment and for protection against fragments. If you're really good at Stealth, dropping grenades into trenches or foxholes at arm's length is very effective.

[Rupert]

Originally Posted by johndallman

High-Tech, p. 190, has the description of using grenades. It is possible to hold the arming handle down while gripping the grenade, so that the fuse timing does not start until it is thrown.

That depends on the type of fuse. The standard ones used these days, and the WWI/II Mills Bomb and 'pineapple' style grenades are all like this, but 'potato mashers' and similar grenades had a string you tugged to start the timer, though I understand a familiar user could do that as part of the throw. They usually had a cap you had to unscrew to be able to pull the cord though, and that took a little extra time.

Yup, less reliability. TL8 grenades should be accurate; TL6 ones might be off by a second.

TL7 grenades certainly were - the M67 grenade of the Vietnam War period (and all its many copies and clones) had a fuse with an official time of 4-7 seconds, usually favouring the lower end.

Standing in the open drawing and throwing grenades is suicidal if there are enemy riflemen around: you need cover both for concealment and for protection against fragments. If you're really good at Stealth, dropping grenades into trenches or foxholes at arm's length is very effective.

That doesn't even take stealth if you're part of an assault. All it takes is a bit of a distraction or suppression of the target by your friends, run up, toss the grenade in, and get to cover. Ideally as soon as a grenade goes boom! you follow it in and finish up anyone who survived.

[Varyon]

Originally Posted by Kaspar

Would the Off-hand penalty apply here if using the left hand?

Yes. I don't think it's stated definitively anywhere in Basic Set (but the "Handedness" box on B14 certainly implies it), but Martial Arts takes it as a given - MA103, when discussing a character using the Multiple Fast Draw rules, has the character take a -4 to draw their dagger with their off hand.

However, note that if the GM feels that grabbing a grenade is something typically done with the off hand, no off hand penalty would be included - like the Main Gauche and Shield skills, the relevant Fast-Draw would include training to get over using the off hand. Failing that, I personally would have no issue with a single instance of the Off Hand Weapon Training Perk applying to both fast-drawing and using the relevant item. In this case, OHWT (Throwing) means you can ignore the -4 to both Fast-Draw and Throwing if using the off hand to grab and toss a grenade.

Originally Posted by Kaspar

Would be more convenient if this could be done one-handed, but I guess in real life they decided that would make grenades too unsafe?

I think most schemes that would allow for one-handed arming of a grenade would have an unacceptably-high chance of arming the grenade when the character dives into a ditch, slams into a wall in a dash for the cover it provides, or even just makes his/her way through thick brush. Those that wouldn't might be too complex to reliably do during the chaos of combat, and/or add an unacceptable amount of cost and mass (and probably increase drag, reducing range) to the weapon. Finally, once you've thrown a grenade, unless you've got a really good throwing arm (or have gravity on your side, like tossing a grenade off the side of a tall building) and are using concussion grenades (fragmentation grenades are pretty much guaranteed to have a greater effective range than a human could throw them), you want to get some cover between yourself and the grenade ASAP, so retaining the ability to fire while the grenade is in flight isn't a high priority.

Originally Posted by Kaspar

If working two handed, the main weapon should be in a sling, so that it can be picked up with a single Ready afterwards.

As GM, I'd probably allow you to pull the pin with the same hand you're holding the weapon in, but you need to reReady the weapon afterward. This avoids the need for a sling... although having one is indeed still a good idea.

Originally Posted by Kaspar

And incidentally, 1 lb thrown object can deal 1d-4 cr damage if it hits directly. Typical speeds of thrown objects would seem to be about ~20m/s so the grenade would usually take a full second in flight. Fuse 3 seconds.

I'll note GURPS typically ignores time of flight. Yes, it should take a full second for the grenade to reach its destination, but in GURPS this is treated as more-or-less instantaneous - that way, a character can't just move into another hex to avoid getting hit in the face by the grenade, but at the same time characters can react to the grenade the same turn you throw it (potentially grabbing and throwing it back in that time, but we'll get to that later).

Originally Posted by Kaspar

Fuse 1 second. Does it explode now or next turn?

Next turn - it's still got a second left.

Originally Posted by Kaspar

But what about a character in the same hex (Distance 0), but not ‘struck directly’? Page 415 mentions ’Contact Explosions’ that ‘deal max possible damage’, so maybe just roll damage dice without any division when standing in the same hex?

I generally feel this is indeed where you just roll damage and don't divide. If you'd like, you could divide by 1.5 - the grenade is functionally at Reach C relative to any other character(s) in the hex, and Reach C can sometimes be approximated as 0.5 yards.

Originally Posted by Kaspar

“A hit is automatic if the explosive attack actually strikes the target.” Ok, but what about additional hits here? Do I still roll for those?

I interpret this as "roll normally, minimum 1 hit." If you roll a miss, it's still 1 hit. I'm not certain if "explosive attack actually strikes the target" is meant to be if the explosive actually struck the target, or if it's "if there's enough damage after division to affect the target, he/she is also struck by at least one fragment." My inclination is actually the latter - most fragmentation weapons generate a massive number of fragments, such that being harmed by the blast wave but not being struck by any fragments is functionally impossible.

Originally Posted by Kaspar

A TL8 Stun Grenade inflicts HT-5 aff (10 yd.) against stun. But there does not seem to be any rules for regular explosions causing stun (aside from a possibility of a major wound) or deafening people.

You don't see bright lights or loud noises generally being able to stun either, unless they're specifically part of a weapon or power with an Affliction. I fear it would slow gameplay to a crawl trying to work out if a given event produced enough light and/or sound to risk stunning (and then calculate the relevant HT penalty), but potentially you could use a table to work this out.

Originally Posted by Kaspar

Throwing the grenade back: The enemy could start reacting on turn 3 (or turn 4 if we account for projectile flight time). By default it is 1 turn to kneel, 1 turn to pick up the grenade (could Fast Draw help here?), 1 turn to throw it away. NOT enough time if reacting on turn four. Or if the thrower aimed for an extra second, ‘cooking off’ the grenade.

Yeah, tossing a grenade back is rarely going to work out. With the rules from Martial Arts, you could potentially manage it in only 2 maneuvers. Basically, instead of using Change Posture to kneel, you use a Dodge and Drop when the grenade is thrown to fall on/near it (this uses up your Retreat, but is otherwise a free action). You can then use Fast-Draw to grab it as a free action, then roll against Acrobatic Stand (which defaults to Acrobatics-6, although you do have the option to give up you active defenses for a +4) to go from lying down to standing with a single Change Posture. The very next second, you can use Attack, Committed Attack, or All Out Attack to throw the grenade back. If you get really lucky on the Acrobatic Stand roll, getting a Critical Success, then standing up only takes a Step, and you can throw the grenade back the very same second. Note this could be described as the character sliding, grabbing the grenade, and tossing it while standing back up, or perhaps diving forward, grabbing the grenade while rolling, and immediately getting back to their feet and throwing. Other methods of throwing it back quickly would be to drop as above but just throw the grenade from a lying position (which should greatly reduce range, but I think in GURPS just reduces skill), or in a cinematic campaign using the Hand Catch Technique with Parry Missile Weapons to snatch the grenade out of the air and throw it back; both of these would allow you to throw the grenade back the same round it was thrown.

Originally Posted by Kaspar

Also I wonder how likely it is for modern grenade fuses to be off by a second or two. Or WW2 grenades, or WW1. Probably less reliability as you go back.

This I don't know, but some variability could certainly be interesting.

[MrFix]

It would be reasonable that the grenade is drawn into main-hand. That way you draw it, pull pin with off-hand, and it is ready to be thrown to your longest range via your strong hand. Thus, if off-hand penalties for fast draw are a thing in your game, Fast-Draw (Grenade) would suffer.

Here's an absolute chad maneuver - you pull the grenade's pin while it is in a grenade pouch. The spoon instantly detaches and countdown begins. Don't try it for grenades mounted on webbing by spoon. Continue using your longarm as needed, keeping mindful of the timer. Then ready the grenade from the pouch as needed and throw it. Much more economical than holding it in hand for 3 seconds. Tricky GM may claim that if you start flying about or dropping, it can slip out though.

[Prince Charon]

Originally Posted by johndallman

If you're really good at Stealth, dropping grenades into trenches or foxholes at arm's length is very effective.

On the other hand, some men who survived WWI had become very good at returning grenades to sender (anecdotally including one Irishman who became a cop in Northern Ireland after the war; his reflexes saved himself and several others during an inspection, when an IRA chap threw a grenade over a wall and the cop threw it back with great speed).

[Varyon]

Originally Posted by MrFix

Here's an absolute chad maneuver - you pull the grenade's pin while it is in a grenade pouch. The spoon instantly detaches and countdown begins. Don't try it for grenades mounted on webbing by spoon. Continue using your longarm as needed, keeping mindful of the timer. Then ready the grenade from the pouch as needed and throw it. Much more economical than holding it in hand for 3 seconds. Tricky GM may claim that if you start flying about or dropping, it can slip out though.

Utterly ridiculous, and risky enough you're probably looking at a Court Martial (for recklessly endangering the poor sods near you) if you survive, but doable without any extra actions. At T-4, you drop your weapon as a free action (but it doesn't fall to the ground, thanks to your rifle sling), then use Fast-Draw (Grenade) to grab the grenade in the pouch, Readying it for arming. The same round, you use the normal Ready action to pull the pin and release the spoon, arming it. At T-3, you drop the grenade as a free action (but it doesn't fall to the ground, as it's still in the pouch), then use Fast-Draw (Rifle) to Ready your weapon again, and may then act normally - Move, Aim, Attack, etc. You continue to act normally at T-2. At T-1, you again drop your weapon as a free action, and use Fast-Draw (Grenade) to grab the grenade, Readying it for throwing, and use an Attack action to toss it at your target. The next round, T+0, it explodes.

Note you're taking a huge risk just to be able to act for the 2 seconds while you're "cooking" the grenade (rather than doing things the typical way, using two Waits after arming the grenade normally) - Failure on that last Fast-Draw (Grenade) roll means you suffer a Contact Explosion (unless, realizing you drew the grenade too late, you convince the GM to let you drop it before it goes off, for normal explosion damage), likely losing your hand if you survive and injuring everyone near you regardless. The GM would also be justified in calling for an IQ roll or similar when you try to grab the grenade - on a Failure, you think you still have time left before it explodes, and thus continue acting normally (normally, this isn't necessary because you aren't continuing to engage in combat, you're taking Wait maneuvers).

Originally Posted by Prince Charon

On the other hand, some men who survived WWI had become very good at returning grenades to sender (anecdotally including one Irishman who became a cop in Northern Ireland after the war; his reflexes saved himself and several others during an inspection, when an IRA chap threw a grenade over a wall and the cop threw it back with great speed).

I think GURPS requiring the character to drop to Kneeling to grab the grenade is overstating things - a crouch should suffice, but require a roll against DX (or appropriate skill) to successfully grab the grenade as a Ready (or penalized Fast-Draw to do so as a free action). Also, catching something that's thrown at rather than to you should be possible without cinematic rules in play, but doing so would typically cause you to take damage to your hand. One of those is probably the kind of thing that Irishman did.

[MrFix]

Originally Posted by Varyon

Utterly ridiculous, and risky enough you're probably looking at a Court Martial (for recklessly endangering the poor sods near you) if you survive, but doable without any extra actions. At T-4, you drop your weapon as a free action (but it doesn't fall to the ground, thanks to your rifle sling), then use Fast-Draw (Grenade) to grab the grenade in the pouch, Readying it for arming. The same round, you use the normal Ready action to pull the pin and release the spoon, arming it. At T-3, you drop the grenade as a free action (but it doesn't fall to the ground, as it's still in the pouch), then use Fast-Draw (Rifle) to Ready your weapon again, and may then act normally - Move, Aim, Attack, etc. You continue to act normally at T-2. At T-1, you again drop your weapon as a free action, and use Fast-Draw (Grenade) to grab the grenade, Readying it for throwing, and use an Attack action to toss it at your target. The next round, T+0, it explodes.

Note you're taking a huge risk just to be able to act for the 2 seconds while you're "cooking" the grenade (rather than doing things the typical way, using two Waits after arming the grenade normally) - Failure on that last Fast-Draw (Grenade) roll means you suffer a Contact Explosion (unless, realizing you drew the grenade too late, you convince the GM to let you drop it before it goes off, for normal explosion damage), likely losing your hand if you survive and injuring everyone near you regardless. The GM would also be justified in calling for an IQ roll or similar when you try to grab the grenade - on a Failure, you think you still have time left before it explodes, and thus continue acting normally (normally, this isn't necessary because you aren't continuing to engage in combat, you're taking Wait maneuvers).



I think GURPS requiring the character to drop to Kneeling to grab the grenade is overstating things - a crouch should suffice, but require a roll against DX (or appropriate skill) to successfully grab the grenade as a Ready (or penalized Fast-Draw to do so as a free action). Also, catching something that's thrown at rather than to you should be possible without cinematic rules in play, but doing so would typically cause you to take damage to your hand. One of those is probably the kind of thing that Irishman did.

I wish I could appeal to GURPS Court Martial.

You don't need the grenade "Ready" to ready it, since it is not an attack but a simple interaction. As such, no need to take the first fast-draw. Ready to pull the pin, then ready to draw it and toss it on next turn. Fast-Draw on pulling the grenade out could be useful at high enough levels. Otherwise, we all play games with dice, does it really matter if it rolls an 18 now, and not on that dodge one second later?

Even better, no need to drop the rifle, GURPS doesn't seem to require you to remove a hand from the weapon as part of a ready maneuver and then return it to the firearm - reloading only covers actions actually spent on reloading, it doesn't tax you 2 ready maneuvers to ungrab a weapon to reach for magazine, and then to re-grab it after reload is finished! Reasonably, a grenade sits in the pouch snuggly enough, and attached to it by spoon, that you can interact with the ring reliably.

[Rupert]

Originally Posted by Kaspar

A TL8 Stun Grenade inflicts HT-5 aff (10 yd.) against stun. But there does not seem to be any rules for regular explosions causing stun (aside from a possibility of a major wound) or deafening people.

High-Tech has extended rules for explosives (including grenades) that include flash blindness and deafness.

[Rupert]

Incidentally, while it's not what the rules say, in my experience pulling the pin is part of the action to throw the grenade. That's how we were trained, anyway.

Also, pulling the pin is not something you'd readily do while also holding a rifle in your off hand - I'd allow it in a game, but it would be a couple of ready actions extra.