Help Understanding Vehicle Combat Rules (2e)

[King Cairo]

Hello! I'm going to be starting my first MGT2 game in a little while and I've been reviewing the rules in preparation, and for some reason the vehicle combat rules aren't clicking for me.

The main thing I can't seem to figure out is, broadly, how to determine relative distance between two vehicles. I get that speed is abstracted with Speed Bands, but I can find no rules for determining specific relative distance, and how that can change (ie. by speeding up/slowing down). This confuses me, considering vehicle weapon ranges are, per the rules, listed in kilometers and not range bands, and the rules supposedly use the same rules as personal combat which include discrete distances and rules that rely on said discrete distances (scopes, range, etc.).

Scenario: A vehicle is equipped with a scoped Laser Cannon and so has a 2.5km range. It is in pursuit of another vehicle. The pursuer has a higher top-speed so it will eventually close the distance needed to be within range of the target, but the target is already at max speed (Speed Band 5), while the pursuer starts out Stopped (Speed Band 0). It intends to close to 2.5km and then remain at that relative distance, adjusting as necessary, until the target is destroyed.

How is this handled, mechanically? There are a number of things I can't figure out from reading the rules.

• How many rounds does it take for the pursuer to get within range? My understanding is it would take 5-rounds to get to Speed Band 5, however rules state you can attack at targets of different Speed Bands (DM-1 for each band difference), so it wouldn't necessarily take 5 rounds to get within range.
• How do you determine the range, in km, between the pursuer and the target? Since vehicle weapon ranges are listed in km and not speed bands, and follow the same rules as personal ranged combat (saving for 1km = extreme without scope instead of 100m), one (presumably) would need to know the exact distance between two vehicles when in combat, yet I find no mechanics to determine what that distance is.

Am I missing something, or is there a disconnect between the rules for Vehicles, and the rules for Vehicle Combat?

 

[nats]

The simple fact is that the vehicle rules are not well designed and don't even work properly. I actually went through the speed table and worked out what km/hr was in m/round. But you still will have to keep track of distances and directions of vehicles in some way which is micromanagement hell. I dont think with the present rules Vehicle Combat is ever going to be very workable mechanic. They should introduce what Cepheus Deluxe have done and just assign positive or negative DMs to hit based on vehicle positioning

 

[King Cairo]

That's unfortunate, but also what I've been coming to realize from poking around on the web and asking on different sites.

How compatible is Cepheus Deluxe with MGT2? Would it be much work transplanting their Vehicle + Chase rules?

 

[Vormaerin]

Depends on what you mean by compatible. Classic Traveller, Cepheus, and Mongoose Traveller all use pretty much identical basic mechanics. The specifics of various subsystems vary, with Classic Traveller generally being the most tactical/detailed and Cepheus the most abstracted and Mongoose in the middle.

 

[King Cairo]

Depends on what you mean by compatible. Classic Traveller, Cepheus, and Mongoose Traveller all use pretty much identical basic mechanics. The specifics of various subsystems vary, with Classic Traveller generally being the most tactical/detailed and Cepheus the most abstracted and Mongoose in the middle.

Gotcha. Sounds like I should check out Cepheus' vehicle rules. I'll obviously check out the rest of the system too but, aside from the confusion with Vehicles, MGT2 sounds like the sweet spot for my group.

 

[kronovan]

IMO the rules in MgT2E for vehicles and vehicle combat are more than decent as far as TTRPGs go. It's why I keep building my heavily Walker focused campaign for it. I play a lot of Battletech tabletop miniatures, and sometimes borrow things from Battletech Total Warfare and Alpha Strike for my Traveller vehicle combat.

How is this handled, mechanically? There are a number of things I can't figure out from reading the rules.

• How many rounds does it take for the pursuer to get within range? My understanding is it would take 5-rounds to get to Speed Band 5, however rules state you can attack at targets of different Speed Bands (DM-1 for each band difference), so it wouldn't necessarily take 5 rounds to get within range.
• How do you determine the range, in km, between the pursuer and the target? Since vehicle weapon ranges are listed in km and not speed bands, and follow the same rules as personal ranged combat (saving for 1km = extreme without scope instead of 100m), one (presumably) would need to know the exact distance between two vehicles when in combat, yet I find no mechanics to determine what that distance is.

Am I missing something, or is there a disconnect between the rules for Vehicles, and the rules for Vehicle Combat?

I don't think there's so much of a disconnect, but what your need to bare in mind is some of the time and motion stats for vehicles.
Like rate of acceleration which is abstracted to +1 speed band per combat round (6 seconds) at Fast speed band or lower, the starting distance between 2 vehicles (could be km or meters), the ranges for any vehicle-mounted weapons, the max speed achievable in a speed band in km/round (6 seconds).
If you divide a speed band's max speed in kph by 600 (60 minutes per hour * 10 rounds per minute) you get the max km/round. With that stat you can see that only a vehicle traveling at max speed in the Very Fast (#6) speed band or faster, can travel more than 1 km in a round on ideal conditions.

A vehicle in the High speed band (#5) can only travel 0.5 km/round at max speed in ideal conditions. So while the target vehicle goes whizzing by an idle vehicle about to pursue it at .5 km/ round , it's still going to take 2 rounds before the targets gone 1 km beyond that point. So a vehicle starting from idle which will be in the Slow speed band (#3) in 2 rounds and which has a scoped or fire control aiming weapon, will be able to effectively fire with minimal penalties. Once you get a handle on the km/round, it gets easy estimate a lot of this. And there's the Dogfight rules to abstract it and make it even easier.

If I'm going to have vehicle combat on maps (only really do this for the slower Walkers or Tracked), I use Catalyst Game Lab's standard Battletech maps which are are roughly 1-1/4" per hex, with each hex representing 30 meters (roughly 100 ft) across. When using those I don't use km/round as my base rate measurement, but instead meters/round. With that rate it's easy to determine the number or hexes a vehicle moving in a speed band can travel in ideal conditions. So on those a vehicle at Idle can move 1 hex/round, Very slow 3/rnd, Slow 6/rnd, Medium 11/rnd, Fast 28/rnd. I rarely bother with speed band higher than Fast as I rarely have ground vehicles capable speed beyond it. Those maps make it easy for targeting , because it's easy to see the 34 hexes that represent firing 1 km distance. I can just use the rules in the MgT2E crb for vehicle combat with those maps - no need to snip anything from any other ruleset. But of course I always have a homebrewed version of BT's Death From Above rule for the Walkers.

 

[Vormaerin]

MgT's vehicle combat rules try to split the difference between an actual miniatures wargame and handwaving it. As mentioned in the too many rules thread, Traveller has a long history of "look, just make a judgement call and roll 2d6+bonuses to resolve it unless you really really need the extra granularity. If you do, then there's these rules." Classic Traveller essentially had entirely self contained wargames for if you needed to get really granular, while Cepheus is generally says "going granular isn't worth it, just make a judgement call and roll". MgT is trying to give some more granularity than the default action (MC judgement) without actually being an entire miniatures ruleset. Whether it succeeds or not depends on what your desired style is as a group of players.

 

[nats]

MgT is trying to give some more granularity than the default action (MC judgement) without actually being an entire miniatures ruleset. Whether it succeeds or not depends on what your desired style is as a group of players.

I think they raise more questions than they answer. Whenever I try to play MgT according to their rule mechanics I often get frustrated. They put me off playing the game and I just go and play a computer game or watch a film that doesnt require so much brain power!

Some of Classic Traveller might have also been micromanagement hell for a table top rpg, but their vector based ship combat was amazing fun and very straight forward to play. CT never detailed vehicle combat though.

Striker covered vehicles but I cant remember what those rules said - I think it was based on wargaming rules and required a massive play area and covered slower vehicles only like tanks and cars moving across rough combat terrain, not fast chases along roads etc.

Like someone mentioned above probably best just making up your own house rules to cover the particular vehicle combat you have in mind based on Cepheus and Mongoose abstract rules for fast chases, or using squares/hexes for slower vehicles.

 

[AdamWillow]

I need some advice on... vehicle combat.

Situation
Traveller's vehicle has two fire arcs. Front and rear. Enemy has only front fire arc. Fight starts when enemy is on the right side of traveller's vehicle.
Initiative is
traveller 1 - front gunner
enemy - pilot/gunner in his fighter plane
traveller 2 - pilot
traveller 3 - rear gunner

First round

T1 can't shoot (no enemy in his fire arc).
Enemy shoots and hits (we count band differences and all the math).
T2 - can he just use minor action to put enemy in one of the fire arcs or does he need to use significant action for dogfight (which he can loose and make things worse)?
T3 - let's say he can shoot after his friend won a dogfight

next round
T1 - shoots (dogfight won)
Enemy - tries to change situation and uses dogfight (minding he has to substract effect from previous dogfight). He wins. He now can attack but used his significant action for that action so can't shoot until his next round.
T2 - pilot can't use dogfight in the same round but can he use "stunt" action to move his ship to fire arc (or even both of them)? It would cancel dogfight result I guess... but it seems fishy (even with DM-2 from the lost dogfight)
T3 - if pilot can use stunt gunner can shoot if stunt is againts the rules, he can't shoot

next round

T1 - same as T3 a moment ago
Enemy - consume his dogfight bonus and shoots
T2 - pilot uses doghfight to change situation...
[...]


To sum up. I have two questions:
1. Can you use a minor action to position the vehicle so that it can target the enemy?
2. Can you use stunt action to cancel the result of lost dogfight?

 

[AnotherDilbert]

To sum up. I have two questions:
1. Can you use a minor action to position the vehicle so that it can target the enemy?

I would say no: a minor action is needed to just maintain control of the vehicle. Moving to target the enemy while he resists is a Dogfight. If the enemy ignores you, it's at least a Manoeuvre action.

2. Can you use stunt action to cancel the result of lost dogfight?

I would say no: You can use Stunt to cheat occasionally, but if it was routine it would be baked into the dogfight roll. If you "cheat" it wouldn't cancel the dogfight result, just allow you to attack when you normally wouldn't. I would probably apply a negative DM to the attack, say as the target flashes by as the vehicle spins.



It is presumably a house rule, but I would say that participating in a dogfight consumes your driver's main action and the vehicle's movement for the round, regardless of who initiated the dogfight. It's an opposed roll; I would rule that you can decline to roll and concede the action, more or less letting the enemy win (if he succeeds on his task), allowing you to do something else instead. You could choose to ignore the dogfight, e.g. to speed away instead, thereby conceding the dogfight roll. I'm not saying it's a good idea, just that it's possible...

To simplify matters slightly, I would make the dogfight roll first and only apply it to this round, like in space combat.

If using fixed forward weapons, I would allow the enemy fighter pilot to fire his weapons as a part of his Dogfight action, with an appropriate DM (-2?).

MULTIPLE TASKS
A Traveller can try to do two or more things at once, like firing a spacecraft’s weapons while also flying, ...
For every extra thing the Traveller is doing, the level of difficulty for each task is made one level harder.

One level difficulty ≈ DM-2.
For simple weapons, such as fixed machine guns or autocannon, I would say that manoeuvring the vehicle and aiming (&firing) the weapon is the same thing, and allow it to be the same action, with no negative DM.


So I would handle the situation something like this:
An enemy fighter approaches, spoiling for a fight. We enter combat, roll for initiative: T1, enemy, T2, T3.
Declare intention: Both the enemy and T2 wants to dogfight.
0: Start with rolling the dogfight roll, consuming both the enemy and T2's main action (the enemy will fire on his initiative). If either side is surprised apply an appropriate DM.
1: T1 may act: fires, if able.
2: The enemy may act: fires, if able. Main action already consumed by the dogfight, includes firing fixed weapons.
3: T2 minor action. Main action already consumed by the dogfight.
4: T3 may act: fires, if able.
New round, start from scratch, only remember the dogfight DM.

 

[AnotherDilbert]

Situation
Traveller's vehicle has two fire arcs. Front and rear. Enemy has only front fire arc. Fight starts when enemy is on the right side of traveller's vehicle.
Initiative is
traveller 1 - front gunner
enemy - pilot/gunner in his fighter plane
traveller 2 - pilot
traveller 3 - rear gunner

This would imply surprise for me. You can't get to that situation without prior agreement.
I would probably start the "situation" further away, allowing you the choice of, say, running away, letting him get closer, or initiate combat at max range.

If he gets close without combat, the one that suddenly starts firing or combat manoeuvres gets some surprise advantage.

 

[AdamWillow]

This would imply surprise for me. You can't get to that situation without prior agreement.
I would probably start the "situation" further away, allowing you the choice of, say, running away, letting him get closer, or initiate combat at max range.

If he gets close without combat, the one that suddenly starts firing or combat manoeuvres gets some surprise advantage.

I agree that it can be a surprise round so an enemy would have a free round of shooting. (if sensors check fails and enemy come to his weapons range)

Great ideas about shooting from fixed weapons when performing another action. I forgot you can use multiple actions during combat.

 

[AnotherDilbert]

The main thing I can't seem to figure out is, broadly, how to determine relative distance between two vehicles. I get that speed is abstracted with Speed Bands, but I can find no rules for determining specific relative distance, and how that can change (ie. by speeding up/slowing down). This confuses me, considering vehicle weapon ranges are, per the rules, listed in kilometers and not range bands, and the rules supposedly use the same rules as personal combat which include discrete distances and rules that rely on said discrete distances (scopes, range, etc.).

Vehicle combat works just like personal combat. You have a position on the map and can move your speed every round. People have fixed max speed, but vehicles have variable speeds (speed bands) and must move their speed every round.

Each round is 6 s, so for each 100 km/h speed, you move 100 000 m/h / 3600 s/h × 6 s/round = ~167 m per round.

You start at some position, map coordinate. In the simplest case you just track relative position, i.e. distance in metres.

Speed bands basically covers acceleration and deceleration. Especially aircraft can't stop on a dime, it takes a few rounds to speed up or slow down.

Scenario: A vehicle is equipped with a scoped Laser Cannon and so has a 2.5km range. It is in pursuit of another vehicle. The pursuer has a higher top-speed so it will eventually close the distance needed to be within range of the target, but the target is already at max speed (Speed Band 5), while the pursuer starts out Stopped (Speed Band 0). It intends to close to 2.5km and then remain at that relative distance, adjusting as necessary, until the target is destroyed.

How is this handled, mechanically? There are a number of things I can't figure out from reading the rules.

• How many rounds does it take for the pursuer to get within range? My understanding is it would take 5-rounds to get to Speed Band 5, however rules state you can attack at targets of different Speed Bands (DM-1 for each band difference), so it wouldn't necessarily take 5 rounds to get within range.

The Referee determines a starting distance, then each vehicle moves its speed each round. When the distance is within extreme range, you can start firing.

Let's say you start at 5 km range. The pursuer is at speed band Stopped (0 km/h), the target is at High speed (~250 km/h). The pursuer will increase speed by one speed band per round until, say, Fast (~400 km/h):

Round	P Speed	P Move	P Position	T Speed	T Move	T Position	Distance
0	0	0	0	300 km/h	500 m	5000 m	5000 m
1	20 km/h	33 m	33 m	300 km/h	500 m	5500 m	5467 m
2	50 km/h	83 m	116 m	300 km/h	500 m	6000 m	5884 m
3	100 km/h	167 m	283 m	300 km/h	500 m	6500 m	6217 m
4	200 km/h	334 m	617 m	300 km/h	500 m	7000 m	6383 m
5	300 km/h	500 m	1117 m	300 km/h	500 m	7500 m	6383 m
6	500 km/h	835 m	1952 m	300 km/h	500 m	8000 m	6048 m
7	500 km/h	835 m	2785 m	300 km/h	500 m	8500 m	5715 m

and so on... it is closing in by 335 m per round, so will get within 2.5 km = 2500 m by round 17 or so.

• How do you determine the range, in km, between the pursuer and the target? Since vehicle weapon ranges are listed in km and not speed bands, and follow the same rules as personal ranged combat (saving for 1km = extreme without scope instead of 100m), one (presumably) would need to know the exact distance between two vehicles when in combat, yet I find no mechanics to determine what that distance is.

When you are "close enough" you can just track the speed band of the vehicles, it's a simplification. Otherwise you track the map position of vehicles, just as you would people. Vehicles are just potentially much faster and has a limit to how much they can change their speed each round.

If you don't care exactly what round the pursuer catches up to the target in the table above, you just say that at some point it does and then you start the combat, and don't bother to track the exact positions. So just start at what would be round 17 above, when you can fire.

Am I missing something, or is there a disconnect between the rules for Vehicles, and the rules for Vehicle Combat?

I don't think there is a disconnect, it works just like personal combat. Each vehicle has a position on the map, a facing, and moves its speed every round. Some vehicles can stand still (ground cars, helicopters, grav), some can't (fixed wing aircraft).