There are a wide variety of grenades in Traveller, and their effects are very different, but I'll start with the standard-issue fragmentation grenade from the core rulebook. The rule for throwing a grenade is the standard 8+ to succeed, and that "Missed attacks with grenades will generally result in nothing
interesting happening unless there are dangerous or amusing targets nearby, at the discretion of the referee." Given that the range of a grenade is 20 meters (not unrealistic, as this means 40 LR, and 80 XR) and the blast radius is 9 meters (also realistic) this rule seems insufficient. Grenades are short ranged weapons, IRL often used indoors or against fortified positions, but obviously can't be TOO short ranged. They do 5D damage in that radius - also realistic. Where exactly it ends up will be a matter of keen interest to everyone in the area. Some on-line discussions suggest random rules for that, often related to the effect of the attack roll, and this seems like a good idea.
Looking at what the military practice suggests about grenades is:
1) while the "injury radius" is 9 meters - meaning if it doesn't land that close, it probably won't do the job, fragments can fly considerably farther and there is no safe distance. So the practice is to throw and immediately get (back) behind cover. As a referee, I would impose a need to expose oneself (minor action), throw (major action), and dodge behind cover, or suffer danger from fragmentation appropriate to the distance from whereever the grenade lands. I would also allow one aiming action too, standing in the open to gauge the target and get a proper throw, as a standing throw is considered better - with the obvious limitation being that the enemy will shoot you if they can while you are standing there.
2) damage is from a combination of concussion and fragmentation if you are close, but only fragmentation if you are far. Especially the concussion can get through body armour IRL, fragmentation less so but it happens. Probably the 5D is enough to represent this. However, it seems like damage should fall off with distance from the blast. I'm not sure what would be a simple rule for this, maybe -1 per dice for every 1-3 meters distance? So on target 5D, 1 -3 meters 5D-5, 4-6 meters 5D -10, 7-9 meters 5D - 15, 10-12 meters 5D - 20, and so on.
3) Grenades usually have a 4 or 5 second fuse, so the better part of a combat round. The rules allow a reaction to a grenade throw, of diving for cover, giving the grenade attack a -2 and in some cases granting the target armour depending on the nature of the cover, at the expense of target loosing his or her next attack. Looking at options people have pursued IRL, this is the recommended one: generally, there is enough time to dive for cover if you see the grenade coming. If it is a surprise, a recon check might be appropriate, though. Also, the diving for cover option really depends on having an option for cover. Often the purpose of the grenade is to force a dilemma on the target: stay in your foxhole and get blown up, or jump out quickly and get shot. A person in a bare empty room with no open doors is going to get the full 5D, but if there is a sturdy sofa handy, the outcome will be totally different - taking cover behind it will expend an action though.
There are stories of soldiers catching or picking up the grenade and throwing away or back at the thrower, but this is not recommended because if it explodes too soon, you've just created an airburst which increases the blast radius and damage potential. As a referee, I'd allow this, with maybe a very difficult athletics dex check, and serious consequences for failure. The other reaction is to jump on the grenade one's self - this would be pretty survivable in some advanced Traveller armour, and actually there are some soldiers that have survived in IRL, albeit badly injured. Doing this is a reliable method of ensuring all the damage goes only to that one person. The problem with putting something on top of it is that it will blow the object up and away and fragmentation will fly out the bottom, unless the object is heavy. This should reduce the damage a lot, though, depending on the object.
4. another thing to think about is the lay of the land, and the potential for the grenade to roll or bounce. If it hits the side of a foxhole, it has a high potential to bounce in, but if it hits inside, it won't be bouncing out. If it lands on some stairs, it is probably going to bounce down them until it either comes to the bottom or explodes on the way. There can't be standard rules for this, but certainly it it something for the referee to think about.
In short, fragmentation grenades are extremely deadly if used under certain specific circumstances, but allow the target some options to react and mitigate the situation. They also have a high potential be dangerous to the user. Adding in some house rules about where the grenade lands could increase suspense, and modelling out their properties more realistically can both allow them to be as deadly as they should be, while also enforcing sensible limits on their use. There is a reason guns see a lot more use than grenades in firefights IRL. Understanding how they are used IRL can also create interesting tactical dilemmas and also offer solutions for the players: in particular you shouldn't be able to throw a grenade without thinking pretty hard about where it is going to end up.
How do you handle fragmentation grenades? Or other types of grenade?
interesting happening unless there are dangerous or amusing targets nearby, at the discretion of the referee." Given that the range of a grenade is 20 meters (not unrealistic, as this means 40 LR, and 80 XR) and the blast radius is 9 meters (also realistic) this rule seems insufficient. Grenades are short ranged weapons, IRL often used indoors or against fortified positions, but obviously can't be TOO short ranged. They do 5D damage in that radius - also realistic. Where exactly it ends up will be a matter of keen interest to everyone in the area. Some on-line discussions suggest random rules for that, often related to the effect of the attack roll, and this seems like a good idea.
Looking at what the military practice suggests about grenades is:
1) while the "injury radius" is 9 meters - meaning if it doesn't land that close, it probably won't do the job, fragments can fly considerably farther and there is no safe distance. So the practice is to throw and immediately get (back) behind cover. As a referee, I would impose a need to expose oneself (minor action), throw (major action), and dodge behind cover, or suffer danger from fragmentation appropriate to the distance from whereever the grenade lands. I would also allow one aiming action too, standing in the open to gauge the target and get a proper throw, as a standing throw is considered better - with the obvious limitation being that the enemy will shoot you if they can while you are standing there.
2) damage is from a combination of concussion and fragmentation if you are close, but only fragmentation if you are far. Especially the concussion can get through body armour IRL, fragmentation less so but it happens. Probably the 5D is enough to represent this. However, it seems like damage should fall off with distance from the blast. I'm not sure what would be a simple rule for this, maybe -1 per dice for every 1-3 meters distance? So on target 5D, 1 -3 meters 5D-5, 4-6 meters 5D -10, 7-9 meters 5D - 15, 10-12 meters 5D - 20, and so on.
3) Grenades usually have a 4 or 5 second fuse, so the better part of a combat round. The rules allow a reaction to a grenade throw, of diving for cover, giving the grenade attack a -2 and in some cases granting the target armour depending on the nature of the cover, at the expense of target loosing his or her next attack. Looking at options people have pursued IRL, this is the recommended one: generally, there is enough time to dive for cover if you see the grenade coming. If it is a surprise, a recon check might be appropriate, though. Also, the diving for cover option really depends on having an option for cover. Often the purpose of the grenade is to force a dilemma on the target: stay in your foxhole and get blown up, or jump out quickly and get shot. A person in a bare empty room with no open doors is going to get the full 5D, but if there is a sturdy sofa handy, the outcome will be totally different - taking cover behind it will expend an action though.
There are stories of soldiers catching or picking up the grenade and throwing away or back at the thrower, but this is not recommended because if it explodes too soon, you've just created an airburst which increases the blast radius and damage potential. As a referee, I'd allow this, with maybe a very difficult athletics dex check, and serious consequences for failure. The other reaction is to jump on the grenade one's self - this would be pretty survivable in some advanced Traveller armour, and actually there are some soldiers that have survived in IRL, albeit badly injured. Doing this is a reliable method of ensuring all the damage goes only to that one person. The problem with putting something on top of it is that it will blow the object up and away and fragmentation will fly out the bottom, unless the object is heavy. This should reduce the damage a lot, though, depending on the object.
4. another thing to think about is the lay of the land, and the potential for the grenade to roll or bounce. If it hits the side of a foxhole, it has a high potential to bounce in, but if it hits inside, it won't be bouncing out. If it lands on some stairs, it is probably going to bounce down them until it either comes to the bottom or explodes on the way. There can't be standard rules for this, but certainly it it something for the referee to think about.
In short, fragmentation grenades are extremely deadly if used under certain specific circumstances, but allow the target some options to react and mitigate the situation. They also have a high potential be dangerous to the user. Adding in some house rules about where the grenade lands could increase suspense, and modelling out their properties more realistically can both allow them to be as deadly as they should be, while also enforcing sensible limits on their use. There is a reason guns see a lot more use than grenades in firefights IRL. Understanding how they are used IRL can also create interesting tactical dilemmas and also offer solutions for the players: in particular you shouldn't be able to throw a grenade without thinking pretty hard about where it is going to end up.
How do you handle fragmentation grenades? Or other types of grenade?
