The short answer is no (if I understand your meaning).
In game terms, you are firing "directly" when the shooter has a line of sight to the target (Shooting, p17). You are firing "indirectly" only when using off-board artillery that is called in on a target visible to the caller (Indirect Artillery Fire, p30).
There are a few weapons that are assumed to come with multiple types of ammo (cannons and missile launchers can fire armour piercing and high explosive shells). Mortars only fire high explosives.
On p21 of the rules, under Shooting a Blast Weapon, it says "When fired at infantry, cannons, mortars and missile launchers all use high explosive shells." This is followed by a rules heading called "Ranging In".
Because you are actually targeting an area when shooting at infantry, and not a specific thing like an enemy tank, the rules for shooting Blast Weapons is different than the normal rules for shooting.
The "Ranging In" rule is basically covering the fact that your weapon may be firing a number of rounds to get the range and location down. You may be firing in an "arc" (but FAD doesn't call that out since it doesn't matter). If you fail, your shots miss the mark. FAD, being "Fast & Dirty" doesn't bother with scattering your attempts to see if something else was hit. You miss, end of story.
So let's take your missile launcher. I'm going to assume it's one guy with a man-portable unit on his shoulder (yes, I'm visualizing a 40K model).
He wants to shoot at an enemy APC. Roll 1d6 (he's an individual) and add the mods that apply (p19). Let's say he is a Regular trooper (so +1) firing at Close Range (Base Range = 4" for Regular, weapon multiplier is 8x so anywhere from 5" to 32" is close range = no mods). He rolls a 4 + 1 so the final result is a 5. The APC is in plain view, so every 3 points is a hit. Missed getting two hits by one point!
To determine penetration, roll 1d6 and add the AT value of the missile launcher (+5). He rolls another 4, so result is a 9.
The APC rolls 1d6 and adds the armour rating of the targeted portion of the vehicle. This was a front shot, and the APC has an armour rating of 5 on the front. He rolls a 3. Only an 8 total.
The missile launcher penetrates, and you roll 1d6 on the Vehicle Damage Table (p20) to determine what happens.
Same missile launching trooper, next activation. He decides to target a squad of infantry visible in a nearby woods.
He rolls 1d6 to "Range In" (p21). He rolls a 5, so he has the range. If he had rolled a 1-4 he would have missed entirely. But he hits, so place a 2" blast radius template over the targeted location.
Only one unit is under the template, so the missile launcher rolls 2d6, adds them together, and then adds any modifiers that apply (lets say none do). He rolls a 7, perfectly average.
The target is partially concealed in the woods, so it takes 4 points to equal a hit. Again, missed a second hit by 1 point.
The missile launcher rolls 1d6 and adds the damage rating of the weapon (missile launcher is +2). The one enemy trooper that might be hit rolls 1d6 and adds his armour rating (he has improved armour, so +1).
Missile trooper rolls a 3+2 for 5 total. The enemy trooper rolls a 4+1 for 5 total. They tie, but the attacker wins ties. The enemy trooper is removed as a casualty (in the basic game), or marked as wounded (if using the advanced rules for Recover Wounded).
Sorry for the long-winded example. Hope that helps.
As to your comment about a missile launcher being a strong AT weapon with a short effective range, I disagree. In my example above, a regular trooper (base range is 4") coupled with a weapon multiplier of 8x means that 0-4" is base range, and 5-32" is close range (which has no penalties to the range).
I play FAD in a 4' x 4' area, so a close (no penalty) range of 32" means it can hit just about anywhere on the board it can see at close range if the missile launcher is about 12" from a board edge.
As for the "medium mortar" with an unlimited range, you are basically correct. Remember, you must still have a LOS and be within range of an enemy to shoot. But, there are NO negative modifiers for range when shooting a blast weapon (this is all taken care of by the Ranging In rule, where 67% of the time you will fail to hit your target).
So that regular quality missile launching trooper, when shooting at infantry, actually has a range of 32-64" medium range, and 65-128" at long range. You would have to be playing on one HUGE table to not be able to target the whole board.
But you MUST have LOS to shoot.
Steve
finally begins Vietnam.
