"Suppression Fire" Topic

I find a lot of low level games don't seem to model this the way I understand it, and are too worried about 'hits'. Suppression is often just a by-product, rather than an aim in itself

3 approaches I know of.

1) CoC – Declaring suppression lessens your effectiveness, but penalises the target.

2) Troops Weapon and Tactics – Declaring Suppression fire halves the number of hits, but increases the chance of pin or suppress.

3) My method in Blood Sweat and Tears. Fire is delayed resolution. You mark the number of fire points against a target. These are not resolved until that unit acts. You declare which action you will take, and the to hit number of each of those FP relies on the action taken- so Movement hit on a 4+, fire 5+, Hunker down on a 6+, placing the suppression effect on the risk as seen by the unit. This isn't an advert for my writing*! I mention it because that's how I see human nature – suppression isn't a function of the firer, but rather the perception of the target. The down side being having to track potential hits until a unit activates.

Any thoughts, rules you like, rules you DON'T like, suggestions, house rules etc.

*However if anybody is into Romantic Fiction I may have a book for you…

Most games ignore suppression. The results of firing or HE effects tend to be either a hit or a miss. I now look for suppression in a new rule set before I buy

Phil Barker's armor/infantry rules from the 80's prominently featured suppression (and "neutralization") effects. When the mortars and artillery started falling people went to ground. Lack of suppression and neutralization effects in rules mechanics (IMO) devalues area weapons (MGs, mortars and artillery) and leads to excessive and unrealistic mobility of units on the tabletop.

FWIW.

B

Some previous useful discussions and articles:

TMP link

link

PDF link (password "cunard")

PDF link (password "harfleur")

link

This is quite thought provoking. It will be interesting to see if this thread develops.

The subject often comes up in relation to HMG suppression fire in WW1 and WW2 rules but I have never seen a satisfactory or smooth solution.

Any thoughts, rules you like, rules you DON'T like, suggestions, house rules etc.

Rules I don't like:

When suppression fire is made a different type of fire than aimed fire (except long-range sniper fire if you must)

When the target has a choice about whether to be suppressed or not

Rules I like:

WRG 1925-1950
-roll to suppress (chance can be quite good, dependent upon weapon and range)
-roll to convert suppression to destruction (chance normally very low for small arms unless within grenade range)
-subsequent morale tests often produce a pleasing indirect suppression effect as an entire platoon hits the deck because one or two of its elements have been suppressed)

Rules I like provisionally:

Nuts! I have just started playing these. The mechanics seem about right, but too early to judge how well they are calibrated. Promising start though (and would probably be more accurate, but less fun for some players, if the "star quality" rules were ditched).

And some more bits:

TMP link

TMP link

TMP link

I also don't like special 'suppressing fire' rules, _all_ fire is suppressive, any hits are a bonus.

So I like:

*just being under fire, any fire, reduces unit effectiveness (eg HE fire in CD)
*it being part of the standard combat resolution (WRG as above, squad leader, crossfire, fireball forward et al)
*suppression being the primary result of fire, especially small arms fire (e.g. Sabins 'Fire & Movement', Squad Leader etc).

I concur with Martin. The first effect of any fire upon a human target is psychological: moreso certainly if the target is taken by surprise; perhaps somewhat less so if the target is prepared to endure fire (entrenched in defense or under positive orders to assault). As such, determination of suppressive effect upon the element/unit should arguably take first precedence, with determination of physical casualties derived secondarily. My opinion FWIW.

I also recall Phil Barker arguing that <<<for the purposes of inducing suppression effect>>> the number of "barks" in a given unit of time is more important than the size of the dog. Make of that what you will, but I'm not sure I disagree.

B

Hail of Fire, a new set of WW II rules I am going to try this weekend, also uses the "Fire Points resolved when the target takes an action" method. I think it sounds interesting.

+1 Martin's comment: all fire is suppressive, any hits are a bonus.

I like TW&T's rule best, but to be clear, it has three different options:

LMG's: Declare "pinning fire" (i.e. continually and steadily firing upon the enemy position, without waiting for a target of opportunity to pop his head up). This halves the chance you will actually cause damage, but greatly improves your chance to pin or even suppress the enemy. At close range or against a clear target, it turns most non-pinning results on the chart into a pinning result and any pinning result into a suppression, so unless you roll poorly (or the shot was a poor or long one to begin with), you have a good chance to pin.

HMG's and MMG's: With HMG's and MMG's, you can also set up a fire lane on top of a known enemy position as well. The moment they move (and any time an enemy passes nearby the fire lane as well) you get a "pinning" fire attack (as above). You also get another normal (or pinning) attack on your card.

You may also choose aggressive fire with an HMG or MMG, which represents focusing entirely on the target and shooting at every target of opportunity. This nets you two attacks at any point after your card is turned, which may be "pinning fire" or normal attacks.

Lots of different ways to control how your machienguns are firing—appropriate for a game called "Troops, Weapons & Tactics"!

In reading through the thread, it would seem that everyone knows what 'suppression' is on the 20th century/modern battlefield.

The effects suggested so far are:

Pinned: unable to move and/or fire
Suppressed: enemy fire reduced
Casualties

How much of 'suppression' is psychological rather than physical?

No one has mentioned morale or the target retreating.

If all fire is suppressive, as Martin suggests, then the simplest was to handle it is as part of the normal combat fire resolution.

Auchtung:

How much of a machine gun's fire [LMG and/or HMG] would be 'controllable' in the manner you suggest? Would commanders give those kinds of orders or would the gunner simply attempt to hit or suppress what was in front of him.

I have read [or seen in movies] a MG placed with the commander indicating what the gun should target. Some rules like CoC have 'overwatch' mechanisms, but I am not certain that plays the same way as you've suggested.

McLaddie -

> When I referred to the first effect of fire being psychological, I was referring to what would be considered a morale effect in wargamer jargon.

> I believe that fire suppression, in one form or another, has existed since the advent of firearms or even projectile weapons on the battlefield.

B

I tried for years to model this and eventually gave up as it degenerated into a welter of arguments and markers and confusion.

What I substituted for suppression was retreats. but remember I have an Army level game. In he game, a stand of infantry is eliminated if it takes a single hit. Stands can take many hits. For each hit it takes it must retreat some distance up to a maximum of about 32" when it is eliminated with no choice in a single turn. So if for example there are 8 stands in a hex and they collectively have 18 hits, the owner can decide to retreat say 6 stands 3 hexes and leave 2 stands remaining in the hex, or he could retreat all stands 2 hexes and an additional 2 stands the third hex, etc. It makes the system much cleaner. They can move back the next turn, and frequently do, but it's much cleaner.

For No end in Sight, we did it like this:

When you shoot, you get X number of firing dice based on weapons and quality.

Those dice are Shock dice which will pin target figures.

You then get to roll half of X as Kill dice to score hits.

f.x. a US fireteam with a SAW and 3 riflemen, all professionals, would roll 10 Shock dice with every 5+ pinning a target and 5 Kill dice, with every 6 landing a hit.

Essentially, pinning should be an integral part of firing and should often be the primary outcome.

@McLadie, well the modes of "control," as I described it, would represent real-world orders like…

Fire lane:
"Keep watch on that alleyway!" (Pre-planned fire lanes are described in many WW2 manuals)

Aggressive fire:
"Concentrate fire on that farm house!" (In TW&T, the option for "aggressive" fire is really just included in order to mechanically differentiate between LMG's and MMG/HMG… The latter having much more ammo to match their rate of fire. An abstraction, to be sure, but one that is intended to represent the liberal expenditure of ammunition that belt-fed heavy machineguns can send down-range without worrying about ammo levels.)

Pinning fire:
"Steady fire on the hilltop. Keep it up!" (Both in WW1 and WW2, a heavy machine gunner might be told to fire continually "pulses" of rounds at a location rather than a visible target, much like plunging fire. This keeps ammunition expenditure down while keeping constant pressure on an enemy position. The downside is that experienced soldiers will quickly figure out that the enemy machinegun is just firing at random and has not yet picked out an actual target's position.)

Effectively we work on the old adage that first you win the firefight and then you assult.

To take ground you need infantry to assault and the enemy to either lose or run away. Suppression is where you win the fire fight be keep in his head down. In the fire fight ther will be some accumulation of fear, fire and fatigue so you cannot expect a unit to do too much before it is really only happy to be on the defensive for a bit.

The only o g he fire we allow is suppressive fire on suspected but not observed targets. It does not do any harm but may keep any enemy from shooting and certainly deter enemy from moving into that ground.

The methodology is not that of WRG but the objectives are similar.

In Blood Sweat and Tears it is a two part thing. Like I said – the activated unit can decide what it wants to do- does it go for the move order, hitting at 4+, fire, where it is hit at 5+, or just hunker down, and wait for the @@@@ storm to pass- so needs a 6 to get hit.

Any hits are rerolled. 1- miss, 2-3 Pin (fire, no move) 4-5 suppress (no firing either), 6 'Kill' – Loss of effectiveness and suppressed.

So the 'To Hit' roll is the men making a decision- from 'probably safe enough' through to 'Nope'. the result is the instinctive reaction "Yeah, we though we could until we tried."

Mentioned above was suppress then assault. Much of the reason was to avoid the fire, fire, fire – oh suppression – now you we assault. You don't actually know what the enemy is feeling until you find out. So you put 5 FP on the enemy, then think 'Hmm, thats a lot of fire on him, lets go for it. He then declares fire at your approach (5+) or hunkers down- less likely to get a bad result, but means you get there unharmed. No one knows until a unit is activated what sort of state it is in.

Contra this is CoC – While I like the game, I don't like the way it handles pinning, which is a long build up over a number of bounds, usually, and is a result of unit disintegration. I've always seen pin/suppress as an immediate short term reaction to a set of circumstances in a discreet moment of time.

I suspect you get an idea if you are likely to suppress a unit by fire. Place in a platoon commander a few times he, not knowing the rules put down fire specified g what was firing and then assaulting. As the rules seemed to meet his expectation it infers that the effect is in part predictable. Hunkering down in an assault may not be a good idea. You want your grenades and final defensive fire to go in. Once on top of you I suspect it's too late.

In this context (assault) it isn't actual hiding – its more not putting your head up for a decent shot as they run in. Assault isn't bayonets, its grenade range

However if anybody is into Romantic Fiction I may have a book for you…

So, LH, are you a romance writer? And your recommended book? You can email the details.

You don't actually know what the enemy is feeling until you find out.

You do, kind of. If he isn't firing and he isn't moving, then he is very probably suppressed. The danger is more getting hit from an unlocated position you haven't suppressed yet.

What I really don't like is where there is a direct relationship between suppression and kill…like (sadly) spearhead, so 2 suppressions = a kill.
Seems a bit lazy and works from the basis that as long as you keep firing at a target even at long range then you will always get results…which doesn't seem to have been the case.
tends to result in players just setting up napoleonic firing lines that blaze away at each other until one side wins.
Much prefer a system like battlefront WWII where there is no direct link,
A two result system generally doesn't work well, adding a third (unrelated) lesser suppression/pin/disorder whatever state seems way better.

Inevitably there is always compromise. In Maneouver Group there is level of suppression that has the target is doing nothing but hugging the ground. However at that point it is no longer possible to do them further damage to them. Effectively they are cowering at the bottom of their trench or found decent cover. While not perfect it does stop the insanity of say tanks simply shooting a platoon of infantry in trenches to death. In the Arab Israli wars the tank crews had to get out to clear trenches after they were fully suppressed. On balance it fixes more problems than it generates and keeps it simple.

McLaddie – I am, by accident. Amateur at the moment. You can contact me at Gmail – Last.Hussar@

With BST you do find out what the enemy is feeling when he tries to activate – your choice is do you launch the assault before you are sure.

I think we've all seen too many WW2 games where it degenerates into an ineffective firefight- it takes some strength to throw a couple of units into a close assault, knowing how dangerous it is. I've been – and umpired – para players losing their cool with the armour column who feel they need to destroy every enemy unit on the relief road.

I do feel at higher level games the main/only way to render a unit a mission kill should be to Assault. Artillery may kill- it is the biggest danger – but sooner or later the PBI needs to go in.

From my experience and training of 3 years in the infantry and small unit tactics, I have to agree with UshCha about winning the firefight. Winning is defined as suppressing the enemy to the point you can safely maneuver on him and assault or force him to withdraw. Attrition is secondary.

You win a firefight with an accurate VOLUME of fire which is different than attrition. Putting out more of a volume than the enemy will instill in him that he is on the losing side. One research paper shows that a round coming within 3 feet of a target every 3 seconds is enough to make him spend more time hiding than shooting.

Video: YouTube link
At 2:10 into the video; "You may have difficulty in locating definite targets. Do not make the mistake of withholding fire".

Also in defense infantry are normally able to hunker down and take full cover from direct small arms fire if they choose to. That will give the initiative to the enemy allowing them to maneuver freely but will keep causalities down in a sustained firefight is putting out less volume. In reality, you do not need to fire at the enemy if he is not exposing himself or attempting to maneuver.

I determine suppression results based on volume against the enemy defense position, not by the number of "hits". To effectively suppress the enemy in a short period of time you need at least 3:1 odds in firepower. A British War Office paper stated that causalities can be as low as 1% per minute in a sustained firefight but there is always a suppressive effect.

You should only be firing at the enemy with the idea of advancing. Sustained fire for the sake of attrition will only bring mortars down on you. Be careful about giving away your position.

Last Hussar: It's my opinion that in a small unit engagement with both sides able to take advantage of available cover it would be almost impossible to eliminate the enemy by small arms fire only. It would take too much time and ammo and not be fun. Whatever rules you are using which frustrate players because a sustained firefight without a flanking move or assault is ineffective are probably pretty accurate. That's one of the problems with miniatures games is players do not know what real tactics are and combat is mainly based on attrition or # of hits.

Wolfgang's Rule #1 in wargaming is "Reality Sucks". That's why you need to design a game that is intuitive, fun and entertaining. That means killing and blowing up stuff!

Wolfhag

One problem I think that seems to occur is that since WRG which had extra points for the attacker is that too many rules appear to have a platoon a side. This will be indecisive and provided one player is sensible and does not attack it will be stalemate or the other guy attacks an dies. You need a company to take out a platoon as a minimum. If it's well engineered in and has supports it will take a lot more.

I have met gamers who just want to shoot and take figures off regardless of reality. That's OK but then it's just a game but for some folk that is what they want but then it's not close to typical reality.

Wolfhag – You've succinctly put the point I was trying to make! Reading what you've written has made something explicit to me, that I've never really thought about- a unit in cover should be hard to shoot to kill. My rules any hits are rerolled – 1-miss 2-3 pin 4-5 Suppress 6 Kill. Im now thinking any kill for a unit in hard cover should be rerolled, and if not a 6 on the reroll it is a suppress

As I type I'm thinking. I was thinking Soft is (for example, I'd need to work the numbers) -1 FP, Hard -2, etc. I might go with All cover gives -1 (for example), with hard or fortified allowing you to so the reroll, and Fortified (actual bunkers etc) allowing you to ignore the first suppress.

It comes under a comment from one of our now keen players. '
"The trouble with your rules is you have to have some idea of what a platoon commander really does". I always take this as a compliment.

Bit slow this week as I am on holiday in foreign lands. The Current US field manuals state the role of Artillery is to suppress and fix in place. This and the publicly available effects planning data has been interpreted by us as the major effect is suppression with some limited attrition. Based on the data we have "cheated" a bit. And have three levels of fire density available using different amounts of ammunition and having different effects. The outset of this is that if you are in a trench and you call down a le v el that us designed to impact troops moving in the open, you in the trench will be unaffected but the troops exposed will be suppressed. This is not hat bad when you look at the odds of being hit close enough to get you in a trench is very low. As always a compromise between the perfect effect and good enough for the purpose intended.

UshCha,
I have to agree about artillery. During a bombardment, defenders are under ground level and not worried about the enemy as they will not attack into their own barrage. The heavy stuff will cause more causalities.

The timing of the suppressive barrage is important as the attacking infantry should hit the enemy just when the barrage lifts. If the infantry is held up or the barrage ends too soon the timing is off and the defender will come out from hiding and be ready for the attack.

Wolfhag

Whirlwind: Those are some good links. Thanks

Here is the direction I'm going with small arms fire to determine attrition, suppression and morale in a sustained firefight with turns of 1 minute or less using stands for infantry teams and crew served MG's. Since small arms fire is figured in volume (and not each figure rolling for a hit or miss) it is resolved at the end of the turn giving enough time to build up a volume that can be effective. The attrition/causality rate is determined by comparing the firepower to the defender target exposure (hard cover gives less exposure) while standing in the open gives full exposure. The result can be from 1% to 100%. The 1% could be light fire against troops in trenches/bunkers and up to 100% could be a surprise flanking fire ambush with automatic weapons at point blank range. Each side is told the causality %. Being told the player an idea of how dangerous and accurate his opponent's fire is and how effective his fire is. Now both sides can elect to take self-preservation measures (avoiding fire) by suppressing themselves (player choice).

There are 5 levels of suppression. Each level represents the defender spending 20% of their time avoiding fire and not being exposed to become a causality. The tradeoff is that their firepower is decreased the same amount. So when the result is a causality, the defender gets a suppression/self-preservation save rolling a D10. A Level 3 suppression will reduce the chance of a causality by 60% but decrease firepower by 60% too.

I'll try to give an example: The enemy firepower has generated a 35% causality rate (all four figures on the stand have a 35% chance of becoming a causality). You feel that's pretty dangerous and put two suppression markers (40%) on your team. Now each figure is checked against the 35% causality chance (I use one die roll on a binomial table) and it results in one causality. Now you roll the D10 for the suppression/self-preservation save for that causality. He saved himself by ducking back/hiding (simulating suppression) if he rolls a 1-4, on a 5-10 he was still exposed and was hit. The down side is now the team is spending 40% of their time not being exposed (simulating suppression) so their firepower is reduced by 40%.

Rather than the player deciding on suppression you can have a method using a die roll, either works. When there are 5 suppression markers the unit must withdraw out of the enemy LOS (100% suppression) simulating a morale break, retreat, rout, etc. After they are safe they can rally and remove all suppression markers.

Another thing that was determined by some of these military/defense research on suppression was that the more suppressed a unit was the harder it was to cause additional causalities because they are spending more time out of direct fire LOS.

Personally I don't like things like a cover save but in the case above I think a suppression save works and eliminates the need for additional firepower modifiers for causalities.

After two rounds of firing if one side has a 3-1 or more firepower superiority they should have reduced the enemy effectiveness below 50% from suppression or from causalities. A 1:1 firefight at medium to long range with no automatic weapons fire will have negligible results and be quite boring wit causality rates low enough not to take much suppression or causalities, as it should be.
Suppression also reduces the unit's aggressiveness making it harder to advance under fire. If they cannot advance they are effectively pinned down. I use an Aggressiveness check modified by training and leadership to see if a unit will attempt to move under fire. If they are not being targeted they do not need to check aggressiveness. This pretty much gives the initiative to the side with more attacking units and requires holding units in reserve to intercept them.

A fire and maneuver tactic for a squad with three teams against one enemy team would be for two of the teams to engage the enemy (call it suppressive or covering fire, whatever you want) and the maneuver team to be under Full Cover (cannot be targeted by small arms fire but not shooting either). Since the maneuver team is not under fire it can advance under fire without an aggressiveness check and the defender is already engaged and with any suppression less able to react. This is the benefit for using the fire & maneuver tactic correctly.

McLaddie: Maybe this addresses some of the morale issues? Letting the player determine the suppression level makes it somewhat psychological.

UshCha: I tell people the problem with my tank combat game is that you need to know what a tank commander and gunner do in an engagement and how real tank gunnery works. Yes, some players just want to roll dice and blow stuff up. There are many other games out there that they can play.

Wolfhag

An interesting side effect of voluntary full suppression is infantry vs tanks. If you re in a trench and tanks come into the position un supported by infantrydown. Any trench worth its salt is tank proof so the tank can roll over them with no risk to either party. Then the tanks are in an interesting position they can have infantry round all sides which they cannot kill and have no way of looking all round at the same time so could be attacked by the infantry poping up. No need for daft moral rules tanks, in this situation feel worried! This is an interesting example how by careful selection of what to model you can get rid of lots of rules making the game simple but at no loss of model integrity.

I think morale and not just suppression is done wrong in most games. But to stay on track, suppression should be part of the morale results. Whether you take no casualties or many, the results will determine whether you get suppressed, run away or stay put and fight on. More casualties would certainly increase the likelihood of a unit running away while few or no casualties would be relatively "easy" morale check to make. Exploding weapons would also hurt the chances of a successful morale check as would close assault.

UshCha,
I agree about the trenches and tanks. I'm still working out the details and definitions for my system.

I differentiate between full suppression (from enemy fire) and Full Cover/Hunkered Down (choice).

The player has three choices for an infantry unit posture: Moving, Improved Position or Hunkered Down.

Moving is exposed with no cover.

Improved Position is the team/section gone to ground and dispersed taking advantage of the terrain they are in. Units in an Improved Position can use direct fire and be targeted and suppressed by direct fire.

Hunkered Down is gone to ground and out of LOS so they cannot fire or be hit by direct fire. They are not suppressed unless it is from indirect fire. Hunkered Down is good for ambushing or avoiding fire when outnumbered or on the losing end of a firefight.

An infantry unit in a prepared slit trench (deep enough that an infantryman can move while standing or bent over) has freedom of movement while being out of LOS and not exposed to direct fire. So in this case, he would neither be suppressed or Hunkered Down, just moving out of LOS like moving behind a wall or building.

This is a training/propaganda film but it gets across the idea:
YouTube link
YouTube link

I think the Germans (and Russians?) pre-positioned AT weapons like mines and smoke grenades in specific locations so whoever cold get to them first could use them. It would be hard to carry around a 12-kilo Tellermine.

Here is one showing tanks engaging entrenched infantry: YouTube link

Wolfhag

Here's how I handled it in Combat Command:

Roll to hit with Concealment as a modfier.

If Hit target rolls a Morale Check. Big bonus if your in Hard Cover.

If you pass your Pinned. If you fail your Dead. If your in Hard Cover you'll usually pass but be Pinned.

In Close Combat (Stands touching) you get no Concealment or Hard Cover Morale Bonus. A Hits a Kill.

But contacting an UnPinned Stand is near suicide.

Arillery ignores Concealment (its an Area Weapon) but mostly just Pins (Hits are Pins unless you double the Hit# then you take a Morale Check. Hard Cover counts but can be negated by bigger guns).

Simple but effective – which is the intent of Combat Command.

Agree that troops don't "roll to suppress" its a by-product of trying to kill 'em but is the most common result esp if target is in hard cover.

TomT

Wolfgang,

looked a t the last video first.

I have always been a bit suspicious of the tank using its weight to fill in a small trench. Even today the ground is invisible to tank crew closer than about 30 when buttoned up. (us field manual). So driver has to get it right to within inches from 30m away in difficult conditions, as the trench is only 24 ins wide for infantry. Also if he gets the angle wrong then he may get stuck. Running over anti tank guns is more likely but could easily damage a track but that is probably an acceptable risk.

In my own rules transition from hunker down always takes some time. It's a bit variable but no time to transition seems unlikely. Troops may do it gingerly to avoid getting hit.

UshCha,
I also doubt the decision to collapse a trench with a tank but I have read a number of accounts that it happened. You should be able to move away in a trench but being in a small bunker would be different. I'd also be afraid of the tread popping off after dirt and debris get pulled onto the drive sprocket.

I don't have a time lag for a team to go from Full Cover to Improved Position to shoot unless under fire. I'm just going from my experience in training and war games.

Wolfhag

Like under fire hiding hiding from a tank is a it u predictable. Move in about otherwise I agree. Out of understanding to c o Munich ti on trenches of good quality and even to a firing step is just an unhinged move.

TomT,
I'm on board with what you've got there.

UshCha, I'd say that combat experienced troops would be more effective at spreading out and taking advantage of available cover.

Regarding psychological effects. I'd say that's where being pinned down comes in. Not moving under fire can be a choice. I use an Aggressiveness Check if attempting to move under fire towards the enemy. Failing the check means you are pinned down. Leadership is a modifier. Issuing an order to Pull Back is always obeyed but can result in causalities.

Wolfhag

Must admit personaly I think morale rules are often over done. In most of the accounts I read troops do what they are supposed to do. Green troops may suppress easier, but not always. The Brits used a lot of green troops on D -Day as they had less understanding of what they were in for. The rest were probably closer to elite so extra motivated. Must admit having said that we treat green as harder to un-suppress.

Again personally we have never seen need to have a rule about pinning. Troops get "pinned" without a rule. What happens (which is how we understood it happened and hence modelled it) was that if sufficient fire was incomming it was no longer possible to advance as all units were continually suppressed, no longer able to advance or retreat. As we understand, it this sort of stalemate if not altered by outside influences may last for long periods with minimal losses to either side. The routes out in our rules look to be credible and analogous with the real world solutions, they are:-
If conditions are acceptable smoke and retreat. Smoke and advance is not acceptable as appearing out of smoke the enemy fires first so unlikely to achieve anything.

Wait for night to slip away.

Get more friendly fire to change the volume of incoming such that the unit is able to move forward.

Attempts to move forward will make for increased losses for no gain. At high losses and some luck (if smoke is not an option) it may be possible to get a few troops out but proably not in a state to be effective again without rest and re – arming taking some hours.

Thus suppression is a key parameter in modelling combat.

In our rules

Another factor is that suppression and its "pinning" effects , makes use of reserves possible on the table top as in the real world. As a unit pinned down, be it a team, squad, platoon or company, if it stays put it will survive long enough for reserves to re balance the fire volumes, un-supress itself due to lower incomming and move forward or back as command decides.

I always kinda liked the way that the Battlegroup series treated it. (d6 system) the default shooting mode is suppression fire. You basically roll a D6 for the unit, with a couple modifiers if memory serves. if you succeed, unit suppressed, if you roll a natural 6, unit suppressed and resolve as a standard shooting attack. If you want to make a standard shooting attack, you have to roll to spot the unit before every attack. basic idea being that you know there is a squad in that hedge over there, so you throw some fire at it to keep their heads down. if you want to kill them, you have to actually see them, rather than the area they are in.

Dabber,
That looks like a lot of dice rolling, which to me seems a waste of time. You could get that, or very close to t g at on a single say D20 role. More time for moving troops. The principal has merit but looks long winded.

This is what's working for me in play testing:

When an infantry unit is first shot at it has a few choices of reaction.

It can hit the deck and return fire (Improved Position taking advantage of available cover). This allows them to reduce causalities and return fire.

It can hit the deck and Hunker Down (full cover) but not return fire. This reduces the chance of a causality even more because they cannot be hit by direct fire.

It can Fall Back to better cover or get out of LOS but will be exposed while moving.

It can make an Aggressiveness Check (die roll) to move under fire. Failing the check it must hit the deck in an Improved Position or Hunker Down. I guess you could say it's similar to a morale check.

When under fire to go from Hunker Down to Improved Position (to return fire) requires an Aggressiveness Check. I think this handles suppression with some "psychological" aspects depending on the players decision to expose themselves and return fire or stay safe.

Keeping an enemy under fire while he chooses to stay Hunkered Down basically keeps him pinned without additional die rolls or checks as unless it is hit by indirect fire.

Wolfhag

It's interesting that the conversation has been about damage and concealment. Here is another suppression model considered by the military:

INTERPRETATION OF THE SUPPRESSION MODEL

An interpretation of the suppression computation
is interesting in several regards.

First, by supposition B inflicts no casualties,
and so all of A may withdraw and live to fight
another day. It is possible that A's force is permanently
disorganized and demoralized, but that is
not inherent in the model.

Second, the battle is won by superior unit
firepower, even though at its outset the total rate
of fire and fire effectiveness of both sides were
equal; unit effectiveness is more influential than
the number of units.

Third, B wins by forcing A to concede B's
tactical objective or else suffer complete suppression
and, by presumption, destruction. Mission
accomplishment is a good way to decide who
won the battle, but it is not the usual way in
analysis, which is to compare casualties. Probably
B's organization and morale will be
stronger after the battle than before it, but again,
the model does not tell us.

Fourth, we should not conclude that A's situation
is hopeless in future battles. Now that we
know the significance of treating a and b (or a
and ß) as time-dependent variables, we may
anticipate battlefield conditions in which A finds
a stronger position with an improved firepower
ratio and so is able to exploit its numerical
advantage.

Fifth, observe that the victory went to the
side whose fire dominated on the battlefield. In a
formal sense this was true by postulation, for we
assumed that attrition played no part. Nevertheless
it is useful to look at how and why the
lethal potential of B's superior fire was decisive.
It was in part because B's fire attenuated A's fire
more rapidly, and in part because after A is
reduced to impotence he must surrender or face
destruction. In war the activation and effective
employment of superior firepower is the central
cause of victory, whether or not casualties determine
the outcome. (Our model ignores movement
for the sake of analytical simplicity, but it is
safe to say battlefield movement unsupported by
covering, suppressive fire is a rare occurrence.
Tactical maneuvering is achieved by an astute
blend of covering fire and movement.)
Page 30 Military Operations Research, Fall 1995

TWO EFFECTS OF FIREPOWER

Sixth, these models are formalisms, whether
basic equations [1], [3] or [5] are used. For one
thing, casualties will occur on both sides. For
another, the reduction of fire on the losing side
caused by the winner's fire will usually not go
all the way to zero. There is a point of diminishing
returns in the suppression effect of fire
towards attenuating enemy fire.

Seventh, as a reminder, ground combat is
our subject. Naval and air combat take their own
form. In the judgment of the author, attrition is
the essential phenomenon, and suppression as a
driving cause of sea and air battle outcomes is
rare.

From: link

Just to add to the discussion.

McLaddie,
On page 18 of this file is the British study of causality rates we discussed last week in Sac: PDF link

This is what I've used as a basis for determining causalities in my system.

Some other factors about suppression (if not mentioned already) is once you suppressed an enemy unit it only took 1/3 of the firepower to keep him suppressed. The greater the degree of suppression the less chance for causalities.

With indirect fire (arty and mortars) it was the number and frequency of the "bangs" (or barks as Blutarski said) that kept the enemy head down. 50x 60mm bangs are more effective than 10x 105mm bangs for suppression.

I would think that in a typical multi-gun barrage the defenders would keep their head down almost 100% of the time as an assault
into their own artillery was unlikely.

Wolfhag

My Laddie, thanks for that.

I think that is roughly where we were heading. Interesting to see the official analysis. In our own rules the performance of a unit deteriorates slowly under fire but realistically to eliminate it it must be heavily suppressed then assaulted to render it ineffective and gain the objective.

I should add that in most cases as a convenient way of modelling an assaulting unit after the assault gets a suppression, this is a 'cheat' way of simulating the vulnerability of a unit to counter attack after it has taken a position but not had time to re organise.

I think this is heading to what I see a s big problem in Wargames- the difficulty in modelling morale/the Human factor. This further ties into the biggest failing – Casualties on the table top.

Gamers feel cheated if figures aren't being removed- that is how you judge the the effectiveness of your fire in most games. But kill rates are far too high in most games, and the only way to rationalise this is that the men are there, just not effective- they are firing without aiming etc. Even saying they are running away doesn't seem to hold much water- I've played games, at all levels, where a unit is still in the game at 1/4 strength. And yes, there are units that famously fight to the last man, but they are notable because it is notable.

While casualties can represent the gradual loss of effectiveness, what happens on the table is loss of footprint, changing the dynamic of the game.

The opposite problem is then brought in – a [20th cent] unit that gets caught in the open at short range WILL get decimated.

I'm going to read with interest the document McLaddie posted.

I think what I'm looking for is a low level 20th century version of Black Powder (of all things) BP doesn't do casualties, and I think that is its strength. The effects of combat is to reduce effectiveness, but it can be 'rallied off' given time and space.