How well a 'Mech can converge (concentrate its weapons fire into any given area) a single or all of its weapons onto a target.
This is the thing that's
really been messed up in MW video games. It seems developers have so far thought that the pilots are the major factor in how well a 'Mech can converge it's weapons - which is wrong. Getting every weapon to hit a single section of a targeted 'Mech is a HARDWARE thing in the BTUniverse. Namely, if you don't have an Advanced Targeting Computer,
your 'Mech won't be able to get its weapon or weapons to hit exactly what section you're aiming at on mobile targets. The advanced TC will be discussed a bit further down. There ARE also a set of hit-location tables that DO represent raw Mechwarrior Gunnery skill - the Called Shot tables. Those are discussed too. Also if a target is immobile any 'Mech, with or without an advanced TC, will be able to get more of it's weapons to concentrate onto a single area of a targeted 'Mech; this is an Aimed Shot.
BESIDES the Called Shot hit location tables that represent the pilot's gunnery skill, these hit-location tables represent the combat performance of
THE BATTLEMECH.
So let's have an example; I'll work this out for a shot to the center of mass of the front of a targeted 'Mech.
Remember, this is just expressing the ability of the 'Mech to converge one or all of its weapons onto the area of the targeted 'Mech that the pilot has indicated,
not weapons or pilot performance; and this is only for shots that have
ALREADY been determined to have hit the targeted 'Mech.
The Basic hit-location table
This first set represents keeping the the reticule on the center of mass ("chest") of the front of the target 'Mech:
There's a 13.89% or 5 out of 36 chance of hitting the right arm
There's a 13.89% or 5 out of 36 chance of hitting the left arm
There's a 11.11% or 1 out of 9 chance of hitting the right leg
There's a 11.11% or 1 out of 9 chance of hitting the left leg
There's a 13.89% or 5 out of 36 chance of hitting the right torso
There's a 13.89% or 5 out of 36 chance of hitting the left torso
There's a 16.67% or 1 out of 6 chance of hitting the center torso
There's a 2.78% or 1 out of 36 chance of hitting the cockpit
What do all these percentages mean in the game? Well, in the DB, they're just pure numbers in a math equation, but for the player it could be expressed visually in the game manual or in
training missions in color coded zones across the target to show how shots will concentrate, depending on what you're aiming at, so people could get a feeling for the combat capability of their 'Mech; and this would go for every type of hit-location table.
Here's the table that gives the data that the above is derived from:
And here's the hit-location table for 'Mechs lying on the ground (or quad 'Mechs):
Called Shot hit-location tables
These are the tables that represent how well a 'Mech's pilot can get their 'Mech to get it to put it's weapons fire into a smaller area of a targeted 'Mech. There are two tables: Call high-low, and Call left-right. Attempting to make a Called Shot adds another +3 to the to-hit number that must be overcome. This means that less of your shots will hit, but those that do hit will concentrate into a smaller area.
In game play terms, you "activate" the called-shot hit-location tables by aiming at specific parts of your target. For example, to use the "aim high" Called Shot table, you'd aim at the target's cockpit, neck, or extreme upper torso.
Called high:
There's a 16.67% or 1 out of 6 chance of hitting the:
Left or right arm, Left, right, or center front torsos, or the cockpit.
(Yes, this means that if anyone tells you that if you that if you aim at his cockpit, you can hit his foot ... they're wrong.)
Called Low:
A 33.34% chance of hitting the right leg
A 33.34% chance of hitting the left leg
A 16.67% or 1 out of 6 chance of hitting the right torso
A 16.67% or 1 out of 6 chance of hitting the left torso
Here's the table for Called Shots aimed high/aimed low.
For Called Shots Left or Right:
You use the normal hit-tables, except you have a +3 modifier, and you use the column one section over from where you would normally aim... for instance, if you call a shot left against a target standing directly in front of you ("in your front arc"), facing you , you use the "left" column on the basic hit table.
This table is used for calling shots Left/Right against a mech with it's front facing directly at you or it's back facing directly at you.
If your target's left or right side is facing you, and you want to aim left/right you use the Advanced hit table, posted above (which gives you a chance to hit their rear torsos).
It should be very obvious by now that the hit-location tables are VERY important. In fact, there is good reason to use the tables we already have as a standard baseline to construct more hit-tables to account for some situations which crop up in the video game format.
Aimed Shots
An Aimed shot is the occasion when a 'Mech
without an advanced Targeting Computer can actually target specific locations against a target.
Without a TC Aimed shots are only possible versus immobile targets, and only direct fire weapons and non-cluster ammunition types are usable for this.
The to-hit modifier for an immobile target is -4 (-5 if you have a TC) if you try and target any part other than the cockpit; cockpit aimed shots have a
+3 to-hit modifier (A TC does not affect the cockpit to-hit). After it is determined how many of your shots connect, all weapons that roll a 6, 7, or 8 on 2d6 hit the location you've chosen. If you don't roll a 6,7, or 8 you don't automatically hit the specific location you aimed for. Instead, you roll on the appropriate normal hit-location table (yes, this can result in hitting the section you targeted anyways).
A 'Mech is considered immobile if it is shut down, it's pilot is unconscious, if it is bracing an arm to try and make a hard shot, if it is hooked to a coolant truck, or is having it's ammo reloaded. Quad 'Mechs that have lost 3 or 4 legs are considered immobile. A bipedal 'Mech that has
lost both legs and both arms is considered immobile. "Immobile" equates to a unit not being able to move on it's own at all.
The Advanced Targeting Computer
This bit of hardware is a game-changer. It is a HIGH reward for big tradeoffs piece of hardware. Besides subtracting 1 from virtually all to-hit modifiers (including those for Called Shots),
it allows your 'Mech to actually target specific locations on a mobile target!
A TC consists of an advanced computer that is far more powerful than the standard BattleMech T&T suite - it is able to adjust for many more variables far more quickly. A TC is not just an advanced computer suite, it also employs recoil compensators, gyroscopic stabilizers, and other hardware attached to the various direct-fire weapons systems mounted in a 'Mech. These components help to overcome weapons drift, muzzle recoil on kinetic weapons, and any erratic targeting inputs induced by the MechWarrior. The size and weight of a TC is directly proportional to the weight of all 'Mech-scale heavy weapons it is connected to. Inner Sphere TC's equal the total weapons weight divided by four, clan TC's divide by 5, and both take up a number of criticals (internal spaces) equal to the calculated tonnage of the TC (rounding up at half tons). Yes, they can get VERY heavy and large quite quickly... no free lunches!
In gameplay, having a TC allows you to make an Aimed Shot (not to be confused with a Called Shot) against *mobile* targets. The differences between a normal Aimed Shot vs an Immobile target and an Aimed Shot against a mobile target using a TC is that there is a +3 to-hit modifier, and it is not possible to target the cockpit on a mobile target. Otherwise, all of the other rules for an Aimed Shot apply. If my wonky math is correct, that's about 1 out of 4 shots that "make" their to-hit number will hit what you've aimed at, on
average, which doesn't sound like much, until you consider that the best odds you can normally get otherwise are 1 out of 6 vs the center torso, or to hit a leg, when calling a shot low (when virtually all there IS to hit is a leg!). In practice, TC aimed shots vs mobile targets are very useful for chiseling a specific part off.
Using a TC to make a shot vs a specific location in game requires turning this function on. With this function off, a 'Mech with a TC behaves just like a 'Mech without one, except you have the advantage of a -1 to-hit modifier for most direct fire weapons types in the vast majority of situations.