Suppressive fire

This is not my own work - I downloaded it from Christian Rotter's website a long time ago.

From Luc Maillet, Luc.Maillet@cert.fr.
This has been extracted from a thread in the mailing list.

Why using Suppressive Fire Rules?

Take a standard submachinegun (which can be considered a 1-dice sustained fire weapon). Shoot at a target (3-round burst, 25 meters). Chances are, you'll get 3 hits after a couple of training sessions. After one month of military instruction, the average hits/rounds fired ratio is close to 17/20. Of course, if you fire long bursts or suppressive fire, then the ratio drops in a very big way... With a standard assault rifle, it's even worse. You get the same ratio at about 100m.

What I want to say is that:

Burst fire hits almost automatically at close range.
Burst fire doesn't hit much at long range.
Suppressive fire doesn't hit much, but the ratio doesn't drop either.
Jam is far too common in 40K.

Changes to the Shooting Rules to make shooting more realistic:

Sustained fire at short range only:
- Each time a sustained fire weapon is used that way, add +1 to the firer's BS for each SF dice used.
- Always roll 1 more sustained fire dice than the n required. Take the best n dice for result.
- Jam occurs only if two ore more dice come up with a 'jam' result.
Sustained fire at long range only:
- Substract 1 from the user's BS.
- Always roll 1 more sustained fire dice than the n required. take the WORST n dice for result.
- Jam occurs only if two or more dice come up with a 'jam' result.
Suppressive fire:
- Suppressive fire is a way to prevent troops from crossing an area. You fire - they duck and forget what they were trying to do.
- Suppressive fire can only be declared if the model didn't move during the movement phase (same as overwatch).
- The model counts as having fired. So he's detected, can be fired upon, cannot fire during the shooting phase, cannot CC, etc...
- The player then specifies a zone that has the following characteristics:
  - It is angular in shape.
  - Its length equals the short range of the weapon in ".
  - Its width at the extreme point is equal to 1", +2" per sustained fire dice the weapon can use.
- Any troop (friendly or foe) entering this zone takes 1 SF dice hits from the weapon, unless they use crawl movement (1/2 standard move, counts as prone).
- Blind/Smoke grenades don't hinder suppressive fire.
- The zone lasts until the firing model's next movement phase.
- Each time suppressive fire is attempted, roll as many SF dice as the weapon normally has. If a 'jam' comes up, then it takes effect immediately (if you don't use the rules above for sustained fire, roll 1 more sustained fire dice than usual).