I posted up a rather off the wall idea for shooting. This idea is based of real shooting concepts, incorporates MOA (minutes of angle) etc, and calculates the base 'auto-hit' range before all the other stuff gets dumped on top. I'm thinking of using this as the basis for working out the rest of the rules.
In the end a PC will get a skill, for example, of 'Pistol:10'. This is short hand for '100% @ 10 yards'. This means up to 10 yards, shooting at a 1" stationary target, with 'perfect' conditions, this PC will hit 100% of the time. Something else would have to happen to make them miss: target movement, distractions etc. but all that comes later.
We can then use this 'base range' of 10, to work out that at 15 yards their chance to hit drops to 50%, and at 20 yards 25%. All derived from messing about with MOA.
It allows a percentile system to scale quite well. It also gives a very good idea of a PC's skill level in relation to the real work (we can even match this calibrated skill level to shooting exam passes for police and military personnel).
Later new skills like 'sniper' or 'marksman' can be added on to adjust the sights to allow for long and extreme range shots where bullet drop and windage have to be taken into account, and even 'flight time' with some type of luck roll (target may move, someone moves in front of the target, wind change, etc.) There are a lot of variables at extreme range.
Sometimes things are some darn obvious they get over looked. While I like the shooting hit rate being calibrated to 100% @ specified range, it may make better design sense that it be calibrated to the weapons 'effective range'.
The effective range of an M16 is 550m, a M-9 pistol 50m.
This way all percentage values, of all characters, are calibrated to the same range when using a specific weapon, and only the percentage value is then needed for the character sheet. Nothing else;
So instead of 100%@25m for a pistol, it would be re-calibrated to the effective range of a pistol (that being 50m). In this instance that would work out at about '25%' (using the old way to extrapolate the score: firstname.lastname@example.org, 25%@50m <- this is the one we want!).
So the final value is simple 25%. Yet we can still work out all the other ranges too.
This means the effective range of the weapon becomes very important in these calculations, and it may be an easier way to sort out the mechanical MOA side of things. Far more intuitive, yet we can always backtrack and go into full analysis mode and work out what is going on.
This sounds like an interesting system. What happens beyond the effective range ? chances to hit keep going down linearly, implying that weapons have infinite range ? And I don't really get the difference between both calibrating systems. Basicaly, if i get it right, you end up with values you need to compare the characteristics of different characters around the same weapon, not to resolve a gunfight, the first solution is in meter, the other in percentage. Both cases involving quite a bit of math (the first solution sounds more intuitive to me tho).
What happens beyond the effective range ? chances to hit keep going down linearly, implying that weapons have infinite range?
The short answer is that weapons have a maximum range. For an M16 it's 3,534m. The chances of hitting anything at that range is tiny.
Using the basic system and ignoring windage, drag, gravity etc. and taking a marksman with a high hit rate of 100% at 550m with an M16, then at 1,100m that's dropped to 25%, at 2,200m it's down to 6.25%.
However, beyond effective range there are other variables that come into play (the above mentioned windage, drag, gravity, etc.) that affect the chances to hit. These will be extra rules and probably grouped under 'sniper'. Applying these extra rules would reduce the chance to hit at 3,000m to 0%, or some very small fraction that any hit would be a complete fluke.
For now the weapon's maximum range is the cut off point.
And I don't really get the difference between both calibrating systems.
The first system says 'pistol:10m'. This works out at '100% at 10m'.
The second system says pistol:4%*. This world out at '4% at 50m'. * specifically 4.69%, rounded down.
They are the same underlying system expressed differently. If you take the first system and increase the range up to 50m it would work out as 4%.
It's just a different way of going about things. The first way works out what range the person will hit 100% of the time, and states that range (i.e. '10m'). The second way works out what the same person's chances are at hitting the target at the pistol's effective range of 50m (i.e. '4%').
It may be a bit mind bending trying to figure out two versions of the same system at the same time...
Basicaly, if i get it right, you end up with values you need to compare the characteristics of different characters around the same weapon, not to resolve a gunfight, the first solution is in meter, the other in percentage. Both cases involving quite a bit of math (the first solution sounds more intuitive to me tho).
Think of this system as simple percentile system, like any other, and start from there.
Using the second version of the system, a skill like 'pistol' would be a simple percentage chance. In the previous example a lowly 4%. As with any other percentile system you would have to roll 4 or less on d100.
The only difference is the way modifiers are worked out for range.
At first 4% seems very low, yet we know that 4% at 50m, using this system is going to yield 100% at 10m.
If this PC with 'pistol:4%' can close the distance down to 10m they can't miss (mind you the target probably can't miss either, and there's dodging, diving for cover etc.)
In game use it's always a simple percentile roll. All the ranges can be worked out before hand and marked on the character sheet.
For a pistol the range bands would be something like '12|25|50|100' for the Tactical Sphere, and '12.5m|18m|25m|37.5m|50m|75m|100m' for Technical Sphere games.
* 6m is actually 128%, so it's more like 8-9m for 100% - but I thought that would be confusing one first look
In the end it would work like any other percentile wargame/ RPG: work out range to target, roll D100 to hit.