I could really use some clarification from Relic on how mortars work:
1) Are Mortars more accurate on targets that are spotted by other units?
2) Are mortars more accurate on units that are directly in their own LoS?
(I ask this, because Ive seen 120mms DEVASTATE infantry that is pracrically next to them)
3) Are mortars coded to be more accurate, the more shots they fire at a guven target?
It is handled by the scatter mechanics:
The scatter angle defines how far to the right or left of the unit the shot can go. If a unit is very close, the distance it can go to the left or right is a lot smaller than when a unit is far away.
The scatter distance and scatter distance max determine how far "before" or "behind" a unit the shot can land. This value increases up to the maximum (scatter distance max) in a manner that is described by the "distance ratio" stat.
I am not sure how the distance ratio actually works (would appreciate input from a few number crunchers
) but I suspect it might be a simple (distance ratio * distance). In any case, the 120mm's lower (0.1) scatter ratio than the 82mm's and 81mm's (0.15) also means that it is more accurate than the normal mortars at "short" ranges. A part of the problem may stem from that.
When firing into (or through?) fog of war, the scatter angle and scatter distance are both multiplied by 1.25, so vision of the target certainly plays a role.
So the answers are
1) yes
2) no (no direct fire hit chance unless possible but implausible bug)
3) no (although the Soviet barrage abilities are slightly more accurate than their auto attack)
In any case, if the explosion radius weren't so large, all those problems wouldn't even exist.
A possible other solution could be to leave all of its scatter/AoE/damage stats and increasing the setup (3.5 s) as well as its for its size short teardown (2.5 s) times and maybe also increase its minimum range (7, same as other mortars).
This would shift the unit from its current role of "mortar, only better in everything" towards being a medium artillery piece. This role is also more representative of its long range and cost.
It would still have its killing power but it would be easier to take out (and harrass), especially with flanks and vehicles. However, I think just decreasing the AoE radius (and adjusting other stats) would be easier.
They looked pretty bunched to me wouldn't a normal mortar of had the same effect?
Possibly, but not necessarily. The chance for at least one soldier to survive a hit like that from a normal mortar isn't bad. The 120mm mortar has twice the damage and 1.5 times the blast radius (which means 225% of the area covered) of a normal mortar. This combination means that the area inside which infantry are annihilated (not just damaged) is much bigger.