If anyone is familiar with the 2nd Edition Mongoose Traveller I would appreciate some help.

Im finding something odd with vehicle damage. On one hand a small car can take only 4 points of damage and has only 2 armor, so a pistol can effectively bring it down in a single shot.

On the other a military APC with a Hull of 90 and some armor to boot can take several shots from the TAC missile (equivalent of a ATGM Im guessing) or any of the big bad plasma guns ans such and not be affected.

What am I missing?

Im trying to work up some additional RPG or LAWS type weapons and if I make them tough enough to take out a light military vehicle they outshine almost anything in the book!

Thoughts?

By the way, I see the entries on AP, APDS and such in the alternate ammo section. That will certainly help against armor ratings a bit but the problem i see in damage v.s. Hull, not armor.
Even if you bypass all armor an 8D weapon firing on a 100Hull vehicle is leaving a good dent at best.

I'm not but it seems unsurprising. Traveller has a long and storied history of having sub-spacecraft vehicle systems which made craft at the far ends of the ranges (like I assume small car would be) have some nonsensical results. I think Fire Fusion and Steel from TNE might be the iconic instance.

The car makes being shootable makes slightly more sense to me than the APC that can't be destroyed by one anti-tank missile.

I don't know the system.

What is the definition of taking damage and being reduced to zero in that system?

If one bullet goes into  car engine, it could cause significant engine damage (though likely not). So if there's a damage table where taking that 4 damage from a bullet just means you roll once on a "bullet damage" table, it could make sense, especially if it took into account where on the car was hit. Damage above 4 to the passenger compartment could have a chance to injure passengers. Damage to the engine compartment by a bullet could have a chance of doing various effects. But yeah if it's "car destroyed" that's silly.

But I find it harder to get how an APC would need multiple anti-tank missiles to take out... though that might just be that I've never even seen the Mongoose Traveller vehicle combat rules.

Well essentially the vehicle takes damage to the HULL Value and when it reaches 0, its out of action. There is a chance on a really good "TO HIT" roll to do a critical hit but that another matter. Its certainly possible, if not probably, to render a vehicle brewed up without ever doing any marginal damage first.

So that Ground Car with HULL 4 or a Bike with 2 and perhaps a point or two of armor is likely to be taken out with a single shot of almost anything. Hell an unarmed attack might do it, certainly one from an animal. This is an established, incredibly successful and popular game system. I simply have to be reading something wrong.

When you deal with space craft they institute a sort of scaling where conventional weapons do x.1 damage to spacecraft and spacecraft weapons do x10 damage to conventional vehicles. This makes sense and seems to work but there is on such scaling for standard rifles, grenades and the like and a vehicle. As it is it makes no sense at all. My pistol can kill a dump truck in a hot or two but my guided missile cant take out an APC.

Yeah, that seems to make no sense, unless as you say, you're missing something.

The high APC damage or low missile damage only makes sense to me if it _is_ about total destruction rather than a knockout. i.e. maybe the first missile hit doesn't vaporize the APC - it just does damage and kills most/all the passengers.

The low car damage only makes sense to be if it's about penetration, not destruction. There are many places a bullet can go right through a car but have no particular effect. Maybe it's just the point where an insurance company calls it a total write-off. ;-)