Rules Question: Laser Rifle vs G/Bike

[silburnl]

This situation came up in my game last night and I'm not sure if I ruled correctly.

Player character is in a position that is being scouted out by enemies riding on G/Bikes. It appears that the PC and his companions have been made by one of the G/Bikers and as his buddy sweeps around to take a closer look, the character takes a couple of rounds to aim (for maximum aim bonus) and then fires upon the G/Bike with a laser sniper rifle.

The G/Bike is a few hundred meters out (so no range modifiers) and tracking from left to right across the PC's field of view at about 180 km/h when the PC takes his shot, but not flying evasively until the G/Biker realises that he is in imminent danger and takes a reaction to dodge the incoming fire. So, questions:

- Would you permit the PC to generate an aim bonus in this situation?

- What negative (if any) would you app'y for the G/Bike's speed?

- What negative would you apply for the G/Biker's reaction dodge?

Regards
Luke

 

[AnotherDilbert]

- Would you permit the PC to generate an aim bonus in this situation?

Yes.

- What negative (if any) would you app'y for the G/Bike's speed?

None, for a skilled rifleman against a target at constant speed with a light-speed weapon.

The rules say -30 for a speed of 180 km/h = 50 m/s, which is 300 m/round, but I find that completely unreasonable.

- What negative would you apply for the G/Biker's reaction dodge?

I believe vehicles should use Evasive Action (p132), not Dodge reaction. But if you allow Dodge I would use DEX+Drive skill.

 

[Old School]

Right, the movement modifier doesn't really scale up well, nor does it take into account the effect of distance on relative movement.

Timing your shot to hit something blowing right by you at 180 kph would be very tough. the effect (think in terms of degrees of movement relative to an aiming point) of that same movement of a target hundreds of yards is much smaller.

I would still give some negative modifier, as even with the attack at the speed of light it still has to be timed correctly, unlike with a stationary target. Off the top of my head I think its a tough shot, so call it -4. With two full rounds of aiming, scope, and decent skill/attribute, he should still make that shot.

Of course, they could let the g/bike get closer. At melee range one good punch should take the bike out . (Traveller Companion did a good job of adjusting the vehicle damage rules).

 

[Anonymous]

I could not make that shot with a rifle. That bike is moving 25x its own length per second.

However it's a laser so whatever - why not just use the rules as printed?

If it's a high tech bike withcombat systems the auto-drive might automatically make zigzags around the course the human steered it.

 

[DickTurpin]

At 600m a grav bike travelling at a speed of 180km/hour would only move about 1mm in the time it would take the laser beam to reach it. Evading or not the G/Bike might as well be sitting still for all the difference it would make to a laser weapon.

Edit: Thinking more on this, the true problem is not the time it takes the laser beam to reach the target, but the time between the firer's brain telling the finger to pull the trigger and the finger actually moving to initiate the shot. If it takes 1/10th of a second, then the G/Bike has moved around 50m in that time. But that is really only an issue if the laser rifle was pointed at a section of sky and the shooter pulled the trigger when the target was in the sights. If the shooter was tracking the G/Bike, the motion of the rifle should eliminate that problem. Once the Biker is aware of his danger and begins to evade, he might be able to throw the shooter off enough to warrant assigning a penalty to the shot.

 

[Anonymous]

Another problem is tracking the target in the scope. I'm assuming he has a scope as it's a sniper rifle. Not knowing how TL 12 scopes work and given that a laser is fast, line-straight, and recoilless, I'm happy to just use the rules as given.

Otherwise I feel 600 meters over iron sights is borderline for a number of reasons, one of which is unaided human vision. However I doubt many of us have experience of 180 kmh targets at 600 meter range - it seems a very military application of guns. I'd be interested in what the military posters think.

 

[Old School]

The more i think about it the tougher this shot gets. You’re in that timing of the projectile is inconsequential, but timing of the trigger pull is not.

Unless its like those movie lasers (or phasers ) where the beam lasts half a second or so. In that case just shoot and let the g/bike drive right into the beam.

 

[silburnl]

Thanks for the responses everybody, my ruling on the night was that the speed of the G/Bike posed a tracking problem, but like AnotherDilbert said at #2 when I sat down the day after and worked out that the rule in the combat section came to a -30 modifier this seemed ridiculously hard.

In the end I was a bit harsher than Old School at #3 and gave the task a gut-feel modifier of -8 at the table. So pretty much impossible to do unless you aimed carefully (ie tracked the target) and it helped if you had skill or technological aids to boot. As it happens the PC doing this had both and so was able to pull off the shot with aplomb.

Once he's splashed the first target he had much more problems with the second however, which started flying evasively and so I ruled that it was impossible to aim. The loss of the +6 aim bonus meant that he came nowhere near hitting before his target got to cover.

I hadn't considered Moppy's point at #7 about keeping the target in frame with the scope. Obviously that would be a really tough problem with the TL5-7 optical scopes we're used to today - but on reflection this is a TL12 device that's Drinaxi made (so actually TL14) so it's probably got all sorts of fancy adaptive zoom features and designation aids that mean these sorts of framing issues are no longer a problem.

Regards
Luke

 

[Old School]

Sounds like a fair ruling and outcome.

 

[phavoc]

Many snipers have a spotter with them who provide the initial target acquisition and tracking. Perhaps your sniper would need to purchase (or has) a secondary scanner that he programs certain parameters. By identifying the target with his sniper scope he could send the info to the automated tracker and let it keep track of one target while he takes care of the second. An overlay targetting beacon could provide direction and distance in his scope that would allow him to track and splash the first target and then quickly acquire the 2nd using his slaved tracking system.

 

[Sigtrygg]

By the time we have laser rifles the smart sight on said rifle will be able to compensate.

Providing the grav vehicle is within the sight's field of view and you can move the rifle to keep the grav vehicle in the field of view then you point the rifle at the target, tell the sight to track the grav vehicle and fire when the rifle tells you too, or better yet just tell the rifle to fire when ready.

 

[phavoc]

That's the issue - having BOTH targets in the sight at the same time. Hence the idea that you have a second device/sight that can zoom out and/or track the other targets. One could hand-wave away the limitations of an optical scope and just technomagically say it works like that. However, since a scope is specifically looking down a barrel of a weapon the view would be relatively fixed and focused on a limited scale. I would think at least.

 

[Old School]

If the computer is tracking both targets simultaneously it might as well take the shot too. Not unreasonable at a high enough tech level, but doesn’t make for good gaming. Surely his companions can see the other approaching targets.

 

[collins355]

Your question highlights the problems with using vehicles/craft in the MGT2 combat system. I find it hard to understand how so much effort could have gone into producing books full of vehicle designs and equipment variations and yet the fundamental flaws in the combat system haven't been addressed.

The "Fast Moving Target" modifiers essentially make any grav vehicle invulnerable if it wants to be.

 

[Anonymous]

Your question highlights the problems with using vehicles/craft in the MGT2 combat system. I find it hard to understand how so much effort could have gone into producing books full of vehicle designs and equipment variations and yet the fundamental flaws in the combat system haven't been addressed.

I agree, and I also disagree. While the rules are crap, making accurate rules for moving targets adds a level of complexity, and someone will still find a situation where they break. How would you do it? Have a modifier based on a combination of speed, direction and distance? I've yet to find a set of rules that actually worked and didn't need a calculator or lookup table.

 

[Linwood]

That’s why I just wing it....

 

[Old School]

The Traveller Companion gives rules that greatly improve vehicle combat, but I think the best bet for hitting a moving target is guidelines for referee discretion. I.e. a moving vehicle at high speed is impossible (14+) difficulty, etc.

 

[phavoc]

If the computer is tracking both targets simultaneously it might as well take the shot too. Not unreasonable at a high enough tech level, but doesn’t make for good gaming. Surely his companions can see the other approaching targets.

There is actually a sniper rifle today like that. It makes an amateur into a killer at a thousand yards. At least at targets. To the best of my knowledge nobody has added in grav bikes at the target range.

 

[Anonymous]

If the computer is tracking both targets simultaneously it might as well take the shot too. Not unreasonable at a high enough tech level, but doesn’t make for good gaming. Surely his companions can see the other approaching targets.

There is actually a sniper rifle today like that. It makes an amateur into a killer at a thousand yards. At least at targets. To the best of my knowledge nobody has added in grav bikes at the target range.

Maybe it's just me, but I take it for granted that such devices exist, as they must obviously do so. Autodriving car must be able to track and ID moving humans in real-time, right?

If the weather is clear and the target is on a contrasting background, the software is one weekend's project (using existing components, of course). Here's a quick demo. You only need the first 10 secondsof the video. The rest is the history of the tech, and how to build it. https://www.youtube.com/watch?v=4eIBisqx9_g.

Making it work on effectively on a battlefield is the hard bit and may take many months or years. I'll bet you their system "kind of" works as they will by virtue of resources, be behind the state of the art, which is the auto-drive car.

 

[Old School]

All those assumptions are reasonable, but I'm far less concerned with the actual tech vs how it affects gameplay. A modern tank moving a 60 kph can hit another tank at a similar speed from 2 km away with a sabot round. If you advance that tech and miniaturize it into a laser rifle scope, then there is no need to roll for a player who is prone shooting a target less than 300 meters away, and skill doesn't matter either. But what fun would that be?