"Good Opportunity Fire Rules" Topic

Thinking about op fire. Imagine the following. Your unit is watching a gap – say, between two buildings. Several enemy units pass across the gap.

Many op rules only allow you to shoot at the first enemy unit. Others create an easily avoided "beaten zone" that affects every unit that moves through it.

Which op fire rules do you think work best?

Many op rules only allow you to shoot at the first enemy unit. Others create an easily avoided "beaten zone" that affects every unit that moves through it.

Which op fire rules do you think work best?

EC:
This is a little confusing.

How is the beaten zone 'easily avoided' for all 'other' rules, but the first enemy unit in all the other rules can't avoid it?

Neither of them 'work' from the way you explain it.

Neither!

The first instance, the unit most likely crosses the space before an effective shot is fired!

In the second, how many units would be effected by this "Beaten Zone"? 3, 5, 10, 20? Exactly where would it end? How much ammo can the firing unit discharge in the time allotted?

Besides, after the first shot, or possibly two, it's no longer Op Fire, as I would consider it ordinary fire from that point on!

Cagey ambushers would know to not just shoot at the first unit to cross their field of view, and perhaps wait for a richer target.

Of course, a bird in the hand beats two in the bush, so I guess it depends upon what exposes itself to the op fire.

I think there should be a skill check to determine if the unit is alert, and engages in op fire, as the enemy crosses in front of them.

Not sure about multiple shots in one turn – depends upon the game system and its rules for multiple shots in a turn, so that needs to be considered as well.

So much of this stuff is dependent on level of game, turn sequence etc.

One of the "best" is the defensive fire phase in Squad Leader, although the use of a grid makes it possible to do things like model area fireceffectscand track the exact location of each enemy squad during movement, which are hard to do in non grid games.

You still get stupid stuff like an entire platoon firing through a gap three feet wide though.

Let me offer a different point of view:

If your terrain setup allows for situations where you need opfire, then the setup of your terrain does not match the granularity of the rules.

Setup of terrain has to match the intended level of the rules: movement and fire distances, turn sequence, etc. Too often, players setup terrain in a too detailed manner, then complain the rules cannot handle certain situations dictated by the terrain.

In other words, don't create gaps between buildings or hills or whatever that give rise to this sort of situation. I know it's very tempting to do so, mea culpa, but one shouldn't do it.

The only type of game in which opfire has any reason of existence are true skirmish games: 1 man = 1 figure, and where figures can e.g. be placed behind a single tree, or the corner of a building, for cover. In that type of of game, you have detailed terrain, and no turn sequence can easily handle all sorts of different situations.

Nevertheless, I can see why opfire is needed in some rulesets, but too often, it's an ugly patch applied to broken design. If your movement, firing and turn sequence are well designed, opfire is a natural component of it all, not an afterthought.

In my own rules, units can only do one thing in an entire turn, so if they op fire during enemy movement then that counts as heir action …. However, I give machine guns and anti-tanks guns a chance to retain their rate of fire, due to their role / function as opportunity fire type systems.

Also agree with Phil above – like me, he uses hexes and that makes it easy to implement a rule that causes the entire hex to block line of sight – not just a building outline, so in effect the 'snap shot' gets excluded from play.

I also have movement levels reduced to 1 hex in the main, so opportunity fire is easier to adjudicate.

The only type of game in which opfire has any reason of existence are true skirmish games: 1 man = 1 figure, and where figures can e.g. be placed behind a single tree, or the corner of a building, for cover. In that type of of game, you have detailed terrain, and no turn sequence can easily handle all sorts of different situations.

and

Cagey ambushers would know to not just shoot at the first unit to cross their field of view, and perhaps wait for a richer target.

Of course, a bird in the hand beats two in the bush, so I guess it depends upon what exposes itself to the op fire.

I think there should be a skill check to determine if the unit is alert, and engages in op fire, as the enemy crosses in front of them.

The way this is handled in Combat Patrol(TM), which is a man-to-man skirmish game, I think addresses the question of whether the unit shoots at the first target to enter its field of view in a clean way. Figures have a Reaction attribute, which can be different for different quality troops. Figures may attempt to interrupt enemy movement by making a roll against their Reaction attribute. In this way the player can decide when to attempt to react (e.g., the first unit or hold fire for a potentially better target later). If the figure passes its reaction roll, it may fire, but the enemy gets the benefit of being a moving target. The shooting figure is then marked as stunned, giving up its next activation, since it has essentially activated "early." (Reaction fire does not get you more activations!) If they fail this roll, they don't get to execute reaction fire. If you fail badly enough, you not only do not get to react, but you are stunned anyway. This slight risk has the desired effect of not turning the entire game into merely reaction fire.

If your terrain setup allows for situations where you need opfire, then the setup of your terrain does not match the granularity of the rules.

Setup of terrain has to match the intended level of the rules: movement and fire distances, turn sequence, etc. Too often, players setup terrain in a too detailed manner, then complain the rules cannot handle certain situations dictated by the terrain.

This. If you are moving platoons built up areas should block LOS and where the door and windows are on a building aren't relevant. Heck, I'd even say this for game like FoW or Battlefront WW-II. Some players forget the ground scale and expect to be able to sight through alleys

For me, opportunity fire is a perfect example of gamers over-thinking rules. If you allow a unit to do one thing per turn, you don't need opportunity fire.

Example.

A unit can move, shoot or change formation in a turn. Choose one.

I move forward into range of an enemy. On his turn, he elects to shoot.

Another way to handle this would be in a game like Featherstone's where both sides move and then both sides shoot. Units that remained stationary would shoot first followed by units that moved.

Both systems work exceedingly well without having to have special opportunity fire rules.

If you allow a unit to do one thing per turn, you don't need opportunity fire.

I understand your argument, but it has not so much to do with opportunity fire.

Opfire is related to visibility between units on one hand, and the moment in the turn sequence when fire takes place on the other hand.

You eliminate the need for opfire by eliminating visibility issues, i.e. make sure no units pop out of cover, move in your field of fire, and pop back into cover.

Advanced Squad Leader.

In general (this is ASL – exceptions for everything)
During the movement phase a unit can fire at least twice, first is at full power, second and later at half. Each shot also puts a residual maker in the hex fired upon equal to half the FP used in the attack – all units entering the hex are attacked with the resid. Finally every shot after the second also counts as a morale check on the unit doing the shooting (since they are most likely about to be swamped by enemies that makes sense).

MGs are also allowed to place a fire lane. Which allows firing at anyone moving in the effected hexes.

Fireball Forward has an interesting mechanism. Each unit (squad) can only fire once per activation (activation is generally a platoon) but an MG can fire multiple times. Suppressed units can not fire defensively – so the first thing to do is suppress the MGs.

Opportunity Fire really seems to be reaction fire to an enemy that comes into your LOS and the chance to fire at them before they disappear. It seems to me to be an unusual solution to a game that has movement that is out of sync with the ROF and rest of the game turn. Like Phil Dutre and Martin Rapier have said. The next logical rule seems to be designating overwatch which artificially complicates things even further.

In a 1:1 game I see opportunity fire and reaction as a timing issue, not one of activating a unit or a skill check. Timing could be simulated with a skill check but all of the skill in the world is not going to have me get the first shot off if someone surprises me at my 6 o'clock.

Let's say you designed a game with 60 second turns, that's not unreasonable right. A typical AT gun ROF would be 4-6 rounds/turn. A vehicle moving at 30kph will travel 500 meters at 30kph in 60 seconds (unless my calculator had a human input error). Moving 500 meters could put you into and out of the LOS multiple times depending on terrain density and could be fired at up to 6 times. Now make up some arbitrary and abstracted ways where, when and how many times to engage that target in a 60 second turn. Good luck with that.

I think the mistake the designer made was turns that are too long in duration. In a 1:1 game simulating individual rounds being fired the turns need to be centered on the ROF, not an arbitrary length. The game should have 10 second turns to realistically accommodate the 6 rounds per minute which means 30kph = 83 meters per turn or 8 meters per second. Now the shooter "reacts" to get the "opportunity" to fire at the moving target within that 10 second turn. So in a 1:1 game it is not unrealistic to use historic turret rotation speed and ROF taken into account and what direction the shooter is pointing in when detecting the target. Less abstraction and special rules are needed.

You can easily see where there will be situations where fast moving units, especially on your flanks, will be able to move from cover to cover or through gaps before being fired at UNLESS you are prepared for them and pointing your gun exactly where they show up. That's good planning and tactics. It has nothing to do with skill or activation. Attacking from two different directions makes it even more difficult for the defender.

I think realistically all units in combat are on "over watch" (or up to 360 degree situational awareness) but you are pointing your gun at the most likely avenue of enemy approach to decrease your reaction time (does that make sense?). Being buttoned up or suppressed increases your reaction time giving the moving unit a better chance to escape being fired at or an attacking infantry unit time to close assault. Better trained and experienced troops will respond more quickly too. Having the enemy show up where you are not pointing your gun also delays engagement and firing. Hopefully he does not beat you to the punch and get the first shot off. If I played a 1:1 game where I skillfully maneuvered into the enemies rear and then he passes a "skill check" or gets "activated" and magically gets the first shot off would pretty much me off.

Extra Crispy – based on your question about firing at units moving through a gap. How would you use the above info (ROF versus movement rate) to solve the problem of shooting at units moving through a gap?

That's how I see it. Evidently I'm in a distinct minority on this concept, no problem.

Wolfhag

Seems entirely logical to me, and I agree on the issue of overly long movement rates before opponents can fire, in general.

Force on Force. It is already built into the system.

Have the figure/unit on overwatch make a D6 roll when an opposing figure/unit moves into view. On an EVEN roll, make the shot. On an ODD roll, the moving figure/unit scoots past before the one on overwatch can fire. Makes it nerve-wracking for both players… ;-)

The alternative approach is that used in 5Core which I really like. All units are on overwatch, and any movement at all is subject to a shot. Effectively movement in sight of the enemy is subject to a morale check.

Easy peasy and little messing around.

Leadjunky,
I've played FOF only once many years ago but have the rules and reread the initiative and reaction test sections. Overall it's a playable system that generates a good interactive feel for small unit combat. I've taken a different approach in my Treadheads system.

FOF uses reaction by non-initiative units that are in LOS of the initiative unit. With Treadheads I use a "Situational Awareness" system where all units that have a LOS can react to enemy activity like movement, firing, turret rotation, etc and everyone is on overwatch so not extra rules. I do not have any initiative rules. We both get to respond to enemy units that appear in our LOS. That's the most important aspect of both games.

Image of the Engagement Play Aid:
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FOF uses a Reaction Test that determines if a non-initiative unit can react/fire before the unit with initiative. Treadheads Situational Awareness rules give a % chance to notice and respond to a threat right away and decide to move or shoot. Each sector has a Situational Awareness value. Rolling a D20 and <= the value means there is no delay in responding to move, shoot, rotate your turret to the target, etc. Rolling > the value means delays. HOWEVER, just because you are able to react without delay does not mean you can fire before the enemy you are responding to. If you find yourself in a poor tactical position you can start moving with no delay. You'll be fired at as a moving target and depending on the reaction time and any delays of your enemy you may be able to move out of LOS before he fires. If he hurries his shot (like minimum aim time) there is a good chance he'll miss.

Treadheads example: On turn #15 you respond to an enemy threat in your 9 o'clock LOS. Using your engagement play aid (see link) you see the factor in that arc is a 12 and your D20 roll is a 15 for a 3 second/turn delay in responding. The play aid also shows it takes 15 seconds to get your turret on the target. You can take a Snap Shot at the target spending one second for aim time and firing on turn #34 (15+19), the soonest you can fire but with a hefty accuracy penalty. That would be OK at short range but most likely a miss at longer ranges. Spending 5 turns aiming will give no accuracy penalty but you may be dead before you get the shot off. While you are doing this your opponent is doing his at the same time and you are not holding up the game if there are more than 2 players. If you feel you are in a tactical disadvantage in getting off the first shot start moving and fire on the move and hope for the best. Play continues on and when the turn comes for a unit to fire it does so and decides it's next shot right away like above (there is no orders phase). Every 5 or 10 turns all units with a movement marker are simultaneously moved. If there is no firing proceed to the next turn.

Taken from the FOF rule book:
FOF Example 1: The US Army player with initiative has placed a fireteam atop of a building with a good view of the table on Overwatch. Later, he activates a fireteam and announces that it is going to exit the building it is currently in, move down the street, get in cover behind some wrecked cars, and fire at an Iraqi unit in a ditch across the street from that position. The non-initiative player announces that his Iraqi unit is going to React to the moving unit and fire at it as it moves out of cover in the building and runs down the street. The initiative player announces that his US Army fireteam on Overwatch will attempt to interrupt the Iraqi unit's Reaction. A Reaction Test is made. The US Army Overwatch fireteam wins the test and a Firepower attack is immediately resolved between it and the non-initiative Iraqi unit. The Overwatch fireteam fires first, causing casualties and a Morale Check that leaves the Iraqi unit Pinned and unable to complete its Reaction. The second US Army fireteam finishes its activation unmolested. The non-initiative unit's return fire at the Overwatch unit is ineffective and causes no casualties.

Example 2: Later in the same turn, the US Army player activates another unit, a Bradley IFV, and announces that it is going to move around the corner of a building and fire its chain gun at a building full of enemy soldiers. The non-initiative player announces that he's going to have a mixed unit of Iraqi soldiers in the building React and fire their AT RPGs at the Bradley as it as it rounds the corner. The initiative player announces that the same US Army Overwatch fireteam from Example 1 is going to interrupt the mixed Iraqi unit. A Reaction Test is made. The Overwatch team fails the Reaction test. The Iraqis will be able to fire their AT RPGs at the Bradley before the Overwatch team can do anything about it. Additionally, since the Overwatch unit failed its Overwatch Reaction test it is no longer on Overwatch. Now a Reaction Test is made between the Bradley and the mixed Iraqi unit to see if the IFV fires first at the Iraqis in the building. The Bradley loses the Reaction Test and the AT RPGs fire before it can react. The RPGs damage
the Bradley's chain gun mount, reducing the vehicle's Firepower by 50%. The Bradley now fires at the Iraqi unit and succeeds in causing a casualty despite the vehicle's reduced Firepower. The Iraqi's pass their Morale Check and stand firm. Now the round of fire between the Iraqi unit and the Overwatch fireteam is resolved. Since this is the Overwatch fireteam's second Overwatch fire, it loses one die of firepower in this attack. Nonetheless, the Overwatch fireteam's fire produces another casualty among the Iraqis. This time the Iraqi unit fails its Morale Check and becomes Pinned. Its return fire at the Overwatch fireteam causes no casualties. As stated previously, the Overwatch unit falls off Overwatch because it failed its Reaction Test. For the rest of this turn it may react to fire directed at it just as any other unit would, but it can no longer engage in Overwatch fire or claim any Overwatch bonus.

FOF has a Fog of War trigger, I have a SNAFU trigger. Both systems give a good feel for interaction and reaction. My evaluation is that FOF uses a more abstracted system relying on chance mainly determined by troop quality (the type of dice they roll). Treadheads is more of a time & action simulation with modifiers for weapons platform performance and troop quality. Situational Awareness checks use a single D20 die roll for both sides against their viewing arc factors to determine if there is any delay. FOF gives an immediate resolution of who shoots first. Treadheads creates some suspense and fog of war as neither side knows exactly when they will shoot at each other in a future turn and it can be simultaneous.

In Treadheads to determine who shoots first takes into account turret rotation time, situational awareness delays (if any), troop experience and any delays caused by suppression, buttoned up, aim time or turret rotation. It's all presented on the engagement play aid. There is nothing to remember or other charts to refer to. First time players have no problem with it. It has less rules because there is no need for over watch, opportunity fire and determining initiative.

The only record keeping I can see in FOF is who is on over watch and the number of times shooting on over watch. In the basic version of Treadheads the player just keeps track of the future turn he'll shoot in and if vehicle buttoned up or unbuttoned. When moving a movement marker is placed by the vehicle showing the speed and direction.

I hope this is an accurate and fair translation of the FOF initiative and reaction rules. Both take a different approach that will not please everyone. Basically FOF is about a chance for initiative and a chance for reaction to players initiative. Treadheads is about timing, weapon platform performance, tactical advantage and troop quality. Chance plays a lesser part and a player's decision can be crucial.

Wolfhag

Opportunity fire has different concepts based on era and weapon types. For early slow loading single shot rifles, opportunity fire would only be available for skirmish games if the shooter did not fire in the immediately preceding fire phase. The shooter is spending time loading and cannot use opportunity fire. If they did not fire that phase, then he would be able to use opportunity fire.

In later eras with more rapid firing weapons then opportunity fire is more likely.

Weasels op fire rules are my favorite, both in "Fivecore" and "…in sight" rules. They each resolve differently, but in both cases, opfire is essentially part of movement. When we play, the moving player rolls the die too. It's just part of movement. Couldn't be faster or easier. :)

To clarify, in "In Sight", moving in the open is a dice roll. If the roll for distance isn't enough to get your tail into cover, you get shot at.

There's no "declaring" of overwatch, as we assume soldiers will fire on available targets as they present themselves.

In all systems the trick is to integrate and match the real world. A sustained fire machine gun as an example can fire Grazeing (sonmetimnes Graving Fire). That is the bullet flys not more than about 3 ft (900 mm) above the ground for a length of about 600mm. This can and is sometimes unobserved with random bursts. In either case any time marching system will need to allow impacts on one or more targets in some way to represent the real world inside the time marching of the model of more than one target crossing at the same/similat time.

Our own rule have a basic bound of 10 minutes but because of rush and rest in the real world, in limited conditions there are flurrys of activity within that overall bound. Because of single element activation system we use, what is sometimes called Op fire is not in our rules but is delt within the bound sub sequence. Is it perfect? No time marching analyses are perfect not even Computational Fluid Dynamics in may cases. However it can be made to adequately represent the overall result. In many cases I find its as hard to understand what the real result should be and so validation can only be done to within the level that the actual result is understood, plus the level of granuality and abstraction neccessary/required.