I've gotten back into the Operational Combat System (OCS) after a few years doing other things, and thought the community might appreciate a somewhat detailed example of play, especially now that we can enhance our reports on BGG using images. So, in the next few installments I will provide a run-through of one player-turn. As I go, I'll try to highlight what makes OCS really fantastic as a gaming system, and what makes playing DAK a real pleasure.

The OCS rules are currently being updated to version 4.0, and that is what I’ll be using here. This latest version has streamlined several sections (most notably air missions) and the result is an even better product.

I will play through part of "Training Scenario #1". This scenario starts at the beginning of Operation Compass, the Allies’ late-1940 counteroffensive against a somewhat-limited and stagnant Italian incursion into western Egypt. With a length of 6 turns (three weeks time) the scenario provides only a glimpse into how an entire campaign (covering 239 turns) could play out. A number of shorter and mid-sized scenarios are also available covering any stage of the fight for eastern north Africa.

To win this scenario, the Commonwealth has to destroy the Italian army in Egypt. A “smashing� victory occurs if the Commonwealth can also capture Bardia, a small port on the opposite side of the Italian defenders.

Here's an overview of the starting positions for each side:


The Commonwealth forces consist of a number of armored battalions of the elite 7th Armored Division and several infantry brigades from the 4th Indian Division, all backed up with artillery and assorted independent units. Also present are three valuable leaders (O’Connor, Gott, and Campbell) who can help stacks move more responsively and improve combat effectiveness. Most of the Commonwealth supplies have been stashed in the town of Mersa Matruh off to the east of the segment of the map shown above. Two smaller supply dumps have also been set up, one just off the map above to the east near the coast, and the other as shown at a crossroads in the southeast corner. In OCS, supply is everything: it limits the extent to which units can maneuver, attack, or defend. The player constantly needs to balance the need to move, attack, or rest and resupply. An attack without a sufficient reserve of supplies will fizzle out.

The Italian forces are almost entirely poorly-rated infantry divisions and artillery, with a few small light tank battalions. All of the Italian supply is cached in coastal cities, and a few fortified defensive positions (called hedgehogs) have been built up along the front. The Italians also have one leader, Maletti, to support their troops, and a special Raggruppamento (“Ragg�) that provides some additional flexibility in mobilizing their forces.

The terrain is mostly open desert with some low hills, but divided starkly by several escarpments (long, impassable cliff-like ridges). These escarpments play a large and interesting role in funneling combat units and supplies.

One of the interesting features of OCS is that each unit can switch between several modes (combat, move, strategic, reserve, exploit, or disorganized), shown by which side of the unit faces up and whether an identifying marker is placed on top. Which mode to be in, and when, plays an important part in success and can lead to some challenging decisions. Shown here are two Italian units (the small 62nd light tank battalion and large Marmarica infantry division) that have started set up in reserve mode. This will allow them flexibility to move more rapidly in response to Commonwealth activity. However, until these reserves are formally released they are unable to attack and have their defensive strength halved due to their limbered stance. Additionally, there are only a few reserve markers available to each side; this limits the extent to which an entire army can be flexibly mobilized.



A few aircraft are also available. The Commonwealth have access to some Hurricanes, Gladiators, and Blenheim IVs; the Italians have CR.42 fighters and Ca.309 and SM.79 bombers.

The basic Commonwealth plan in this scenario is to push north to the coast and break up Italian supply lines to the towns of Buq Buq and Sidi el Barrani, while also pushing westward toward Sollum. If things go well, the Commonwealth will then turn north to capture Bardia. One of the great aspects of OCS is that it is eminently possible to defeat enemy units by maneuvering to cut off their supply rather than attacking them head-on. In fact, outright frontal assaults quickly drain supplies and leave an exhausted force, out of fuel, that is helpless to respond to enemy maneuvers. So, while some Commonwealth units will attack key Italian defenders, the main goal is to actually move around most of the defensive positions and cut off their supplies, leading to surrender.



In the next installment, we'll start the game!

Turn 1: 8 December 1940

I. Pre-Turn Phase
1. Weather: roll is 1,6 = clear
2. First player determination: Commonwealth goes first by scenario design

II. Commonwealth Turn 1
A. Aircraft refit: no inactive aircraft, so no actions needed
B. Reinforcement phase: 2 Supply Points (SP) arrive at Mersa Matruh (off the map to the east), bringing the total there to 13 SP.
C. Mode determination and movement phase
i. breakout segment: none
ii. Mode & movement segment:

The first action is to fuel the entire 7th Armored Division. This costs 1 SP and will allow every unit within that Division to move this turn. There’s an “organic truck� for the 7th Armored division in hex 35.18 (under the AT gun) which is used to supply the necessary SP. Later, we’ll move that truck back to Mersa Matruh to reload with supplies.



We flip the 7th Armored Division marker (not shown here) to its fueled side to keep track that all of its units have gas.

Without fuel, only ‘leg’ movement units can move (the other movement types are track and truck). Leg units are those with a white movement factor (the rightmost value at the bottom of each counter); track units have a red movement factor, and truck units have a black movement factor.

Next, the Commonwealth sends a sortie of Hurricanes from their airstrip at Ghat Wahas to Buq Buq to engage the Italian CR.42s. This fighter sweep is intended to draw the Italian fighters out so that they are unable to engage future Allied bombing missions. The Hurricanes have an air combat rating of 3 to the CR.42’s 2, so they have an edge in the combat.



Air combat is very simplified: roll two dice, add the attacker’s combat rating and subtract the defender’s rating. 6-or-less and the attacker must abort, 8-or-higher and the defender must abort, otherwise both abort. A third die is used to determine whether an aborting aircraft suffers a step loss (1/3 chance).

Air combat roll is a 3, which is adjusted to a 4. A third die shows that no abort loss occurs. Despite being the better aircraft, the Hurricanes botch their sweep and wind up returning to Ghat Wahas to refuel.

Next, a Gladiator squadron is sent from Mersa Matruh to Buq Buq. The Gladiators are essentially equal to the CR.42s (2 combat rating) but the Commonwealth is going to take its chances in the hope that the Italian air defense can be weakened. The air combat roll is a 6, again resulting in the attacker aborting (no losses either side).

Now, time for some ground combat! During movement, a special attack called an overrun is possible. As we’ll see, there are a number of stages to run through when conducting combat. A stack of three armored battalions (1st Royal Tank Regiment, 8th Hussars, 3rd Hussars) led by O’Connor move along the road from their initial position co-located with the Western Desert HQ to just east of a small Italian hedgehog containing a single machinegun battalion. This move takes 2 movement points (MPs). The stack then performs an overrun attack on the Italian position (3 more MPs, plus combat supply).



To attack in OCS, each combat unit step must expend ¼ SP (also called 1T or Token; 4T = 1 SP). So, to supply this attack, the Commonwealth must burn 3T supplies, which it does from the 3 SP dump to the east of the Western Desert HQ. The HQ is able to reach out a distance of 5 MPs to that supply dump and then “throw� the supply as far as 8 MPs (as marked on this HQ) to the hungry 7th Armored Division units.

Defenders in a combat need to pay a flat 1T or 2T (depending on size) or else be forced to defend at half strength. The defending machineguns choose to pay the 1T supply cost using the dump at Buq Buq (which they are able to reach because it is within 5 MPs of their position).

Next, each side declares its Action Rating (AR) in the attack. Each unit has an AR shown by the small number in the center of the counter. Higher ARs lead to higher likelihood of combat success, but any losses must first come from the unit whose AR was used to lead the attack. In DAK, leaders can also support an attack and increase the AR by 1, but might suffer wounding, capture, or even death in the process. In this case, the Commonwealth declares that the 8th Hussars are leading the attack (5 AR) also supported by O’Connor, for a final AR of 6. The Italian defender is actually quite good as Italians go, with an AR of 3. The leader loss check is a 10, well above the 6 needed to keep O’Connor safe and sound.

The combat odds depend on attack ratings (left-most value on the counter) and on the terrain and attacker and defender types. Normally, armored (yellow) and mechanized (red) units have their attack strengths doubled in open terrain. However, against a hedgehog (or other anti-tank defense) this is reduced to a factor of 1.5. The total attack strength is then (4+2+2)x1.5 = 12, against a defense strength of 3, for final combat odds of 4:1.

The next step is to determine whether there is any surprise in the combat. I actually don't like the term surprise; what this represents is how better training or preparedness may result in an easier, more successful attack than simple combat odds would suggest. It makes each unit's combat value more subtle. Surprise is handled by rolling two dice, adding attacker AR, subtracting defender AR, and subtracting one more for the hedgehog defenses. If the result is 9 or more in an overrun (10 or more in a regular attack) then attacker surprise occurs; if the result is 6 or less in an overrun (5 or less in a regular attack) then defender surprise occurs. When surprise occurs, the column used in the combat results table is shifted left or right by as many columns as a subsequent die roll. This can lead to much larger or smaller combat odds than originally expected.

In this case, the surprise roll is a 7 (+6 attacker AR -3 defender AR -1 hedgehog) = 9 which results in attacker surprise! The Commonwealth armored units have caught the Italians in their tents. The subsequent die roll is a 4, pushing the combat column from 4:1 to the 11:1 column.



Finally, we roll two dice to resolve the combat (again adjusting for the AR difference and subtracting the hedgehog level). The dice yield a paltry 2 which is adjusted to a 4. The results are then “Ao1 DL1o1�: The defender must lose 1 step (DL1) and has the option to either lose one more step or retreat one hex (o1). The attacker also has the option to lose one step or retreat one hex (Ao1), and should the attacker exercise the option to retreat, the defender need not exercise his option.

Since units are at a premium, the Commonwealth decides to retreat rather than lose the 8th Hussars (a unit with only a single step). The Italians, however, must lose their single-step machinegun battalion.



The rest of the movement phase continues without any overrun attacks. Several units move from Mersa Matruh to reinforce positions to the east of the Italians along the coast. Units in the center push northwards toward the coast. The northernmost unit (11th Indian infantry brigade) actually blocks the supply line from the west to Sidi el Barrani, at least until Italian units move to cover the road adjacent to the Commonwealth unit. Movement is finished off running several trucks to and from Mersa Matruh to replenish supply dumps near the front.

Final positions at the end of the Commonwealth movement segment.


The last part of the mode determination and movement phase is a barrage segment wherein aircraft and ships can conduct barrage attacks. A group of Blenheims fly from Mersa Matruh to the main Italian defensive hedgehog and bombard it.



First, the bombers must survive defensive flak or possible interception by the still-active Italian CR.42 fighters. The Italians decide not to intercept so that their fighters can remain active. However, flak still is used. This involves rolling two dice and adding modifiers depending on whether the hex of interest is within a patrol zone (this one is) and other defenses in the hex. The roll here is a 10, modified to a 12 which results in a step-loss to the Blenheims. Their barrage rating is reduced from a 3 to a 2.

The barrage is then conducted (2 factors, shifted left 1 column due to the hedgehog). The resulting roll (10) is no effect. Note that one interesting aspect of barrages is that the more densely packed the target hex is, the more likely it is for casualties to result.

This scenario also allows the Commonwealth to conduct 12-factor Naval barrages against coastal targets on the first two turns. An attempted barrage against Sidi el Barrani is ineffective.

D. Supply phase.
Each Commonwealth unit is now checked to determine whether it is in “trace supply�. This requires being within 5 MPs of a road leading to a port or railroad from which supplies can be obtained, or within the throw distance of an HQ that itself is in trace supply. In this case, all Commonwealth units are in trace supply.

If a unit is not in trace supply, it must either use up SPs on the map (if within range) or be marked as out of supply and suffer potential attrition effects. Worst case, an unsupplied unit can be completely destroyed in this phase (it surrenders).

Coming later, the rest of the Commonwealth turn...

E. Reaction phase:

Now it is the Italians’ turn to try to react to the Commonwealth movement. Units can be released from reserve and/or leaders and Raggs can attempt to move their stacks. Any of these active units can move (at ½ of their movement allowance), overrun, and conduct barrages. Ragg Babini is successfully activated (rolling a 4, which is at least the 4 needed to activate it). The Ragg expends 3T fuel to move the three armored units that it is stacked with. By staying in the Ragg, these units will also be fueled during the Italian player turn and so will be able to continue to move. Two other reserve stacks are released and move slightly southeast to better cover the coastal roads leading into Sollum.



Seeing as things are getting warm near Buq Buq, the CR.42 squadron rebases to Sollum. As a fighter unit traveling within its range, it even gets to stay active.


Next, the two Italian bomber groups move to barrage Commonwealth airstrip at Ghat Wahas.


They undergo flak that results in a step loss (randomly allocated to the Ca.309 unit). The resulting 6-factor barrage has no effect and the bombers return to their airstrips, inactive.

F. Combat Phase:

Now back to the Commonwealth player to conduct ground combat.

i. Barrage segment

To soften up one of the hedgehogs, the Commonwealth decides that it is worth some supplies to barrage the position with artillery units in hex C38.19. A total of 32 barrage factors are applied, which costs 4T in supply from the southern supply dump.




The barrage is shifted left one column due to the hedgehog. A roll of two dice yields a 6, which is enough to disorganize the defenders. A “DG� marker is placed on their stack, and they now have halved combat and movement factors and a -1 modifier to their AR value.



Spurred on by this success, the Commonwealth also spends supplies to barrage another Italian hedgehog to the west using the 4th Royal Horse Artillery (RHA) Regiment.



There is a somewhat dense grouping of units in the target hex, where density is measured in Regimental Equivalents (RE). Maximum staking in any one hex is 10 RE. This target hex has a total of 4.5 RE (0.5 from 20th Light Tank battalion, 3 from Cirene Division, 1 from the 21 Italian HQ). The result is a shift of two column to the right on the barrage table (which is only partially offset by a 1-column shift to the left due to the hedgehog). The 5 barrage factors then attack on the 8-11 factor column. An excellent roll of 11 results in an outcome of “1/2� which means that there is a 50% chance of a step loss plus all defenders are disorganized. The step loss is realized, and the Italians kill off the light tank unit (figuring they won’t be able to afford any fuel to move it later anyway).

ii. Combat segment

With two disorganized defensive positions, the Commonwealth can’t turn down the opportunity to attack them in force. Three units decide to contribute to the attack (plus the leader Campbell) for a total supply cost of 3T. The Italian defenders pay their 2T supply cost.



Attacker AR is 4 (+1 more for Campbell) against 1 on the defense (2 reduced by 1 for being disorganized). Leader loss check comes out ok for Campbell, who is not wounded or killed in this action. Combat odds are 10:8.5 which reduces to 1.17:1 = 1:1.

The surprise roll is a surprising 12 (+5 for attacker AR – 1 for defender AR -1 for hedgehog) = 15. The shift die roll is a 3, moving the combat from the 1:1 column to the 4:1 column. The combat roll is a 10 (modified to 13) for a result of Ae3 DL2o2DG. This translates to:
Attackers with ARs of at least 3 are placed in Exploitation mode
Defender must lose 2 steps, and then some combination of 2 more steps or retreat hexes, and all defenders are disorganized (which they already are).

Multiple step losses must come from different units where possible, so the Cirene division loses one step and the HQ is destroyed. The divison then retreats two hexes and the Commonwealth 16th Infantry Brigade and Campbell move into the hex the defenders just vacated.



To the north, the 11th Indian brigade engages the 64th Machinegun battalion. This costs 1T on each side. ARs are 4 on the attack and 3 on the defense, and odds are 6:2 or 3:1.



Surprise roll is 9, adjusted to 10 which just barely results in attacker surprise and a subsequent shift of 1 column to the 4:1 column. Attack roll is a 6 (adjusted to 7) which results in Ao1DL1o1. This kills off the machinegun battalion, and the 11th Indian brigade chooses to retreat one hex rather than take a step loss (brigades in DAK have two steps).



The final attack in the combat segment is a large-scale assault on the disorganized stack of Italians (and General Maletti) in the small town of Nibeiwa. A total of 4 Commonwealth units participate, burning 1T from the 4th Indian Division organic truck and 3T from the nearby HQ supply dump. There are 2RE of defenders, requiring a payment of 2T, which the Italians do using their stocks in Sidi el Barrani.



ARs are 5 (+1 for Gott) on the attack vs. 4 (+1 for Maletti) on the defense, or 6 vs. 5, and both leaders are fine.

Combat odds are 24:5.5 which reduces to 4.4:1 or the 4:1 column. (Note that unlike most other games, had the odds been 4.5:1 they would have rounded up to the 5:1 column).

The surprise roll is 8, modified to 9, resulting in no surprise for either side. The combat roll is another 12! modified to 13, resulting in Ae3DL2o2DG again.

The Italians must unfortunately kill off their elite camel-back-riding Sahariano battalion since they used its AR in their defense. They also kill off the Maletti artillery battalion and retreat two hexes. Some of the attackers take up position in the hedgehog that was just vacated.

G. Exploitation Phase:

i. Movement segment.

Now, units marked with exploitation markers can move to capitalize on the fluid situation at the front.

First, the 6th and 7th Royal Tank Regiments attempt to overrun the adjacent hedgehog containing the 5th Libyan battalion. This requires 2T on the attack, and 1T on the defense. ARs are 5 vs. 2, and combat odds are 10:3 or 3:1 (the defenders are positioned in low hills which prevents the Commonwealth armored units from gaining an attack multiple that applies in open terrain).



No surprise results, and the outcome of the combat is Ao1Do1. The attackers decide to retreat rather than take the (permanent) step loss. Since the attackers chose to retreat, the defenders need not take a loss or retreat, and in fact they choose to stay in place.

The other exploit-mode Commonwealth units move but do not attack in any overruns at this time (supply is getting very tight now indeed!)



Finally, O’Connor (under the 4RHA unit) attempts to activate (3 or better on one die), which he does. This allows him to move a couple additional units in the exploitation phase.

As an example of some of the mobility possible in this desert terrain, the 1st Royal Tank Regiment moves out nearly all the way to Sollum while the 3rd Hussars battalion shifts west to cut supply to the remaining Italian hedgehog in the southwest. O’Connor and two other units also shift west adjacent to the disorganized Cirene division (though they are separated by an escarpment). The 1RTR unit is now placed in position to block Italian supply along the road between Sollum and BuqBuq. Unless the 1RTR is dislodged or Italian units move in to cover the supply lines, all of the Italian units east of Sollum will be out of supply and may suffer attrition or surrender.



ii. Barrage. No barrages are conducted.
iii. Combat segment. No combat occurs either.

H. Clean up phase.

Exploitation and DG markers are removed from Commonwealth units and the 7th Armored Divison marker is returned to its unfueled state.

Overview at the end of Commonwealth Turn 1


The Commonwealth has made significant progress toward cutting off supply lines to the eastern group of Italians, but it has come at a large cost in supplies. Only 3T remain to the southeast in trucks or supply dumps, meaning that defending against any large-scale Italian counterattacks may have to be paid for from supplies internal to Commonwealth units.

One of the exciting challenges in OCS is deciding when it is worth paying supplies to conduct combat. It is quite possible that the Commonwealth could have made similar inroads into the Italian defensive positions without expending quite so much supply. Then again, the barrages helped soften up several Italian positions, and the combat led to exploit mode units which were able to push deeper.

At this point, the Italians have a 9T supply reserve between Sidi el Barrani and BuqBuq, but they will have trouble ensuring they can receive trace supply during their half of the turn. In addition to the 1RTR unit, the 11th Indian and 5th Indian brigades also block the coastal road that the Italians rely on to trace their supply lines to Sollum.


Summary of supply usage (measured in SP):

Commonwealth
Starting supply: 19.00
Reinforcement supply: 2.00
Fuel: 2.00
Barrage: 1.50
Combat: 3.25
Remaining: 14.25

Italians
Starting supply: 6.75
Reinforcement supply: 0
Fuel: 0.75
Barrage: 0
Combat: 1.75
Remaining: 4.25

(edit: added supply summary)

Whoa. Jim this is excellent; As far as I know this is the only OCS example of play in existence.

Thank you!

What I would dearly love to see is an example of play for the Race for Tunis scenario from OCS Tunisia. With air-transport, shipping and rail conversion it can get somewhat fiddly; Seeing as many new players are using Tunisia as a starting point I think it would be incredibly useful.

My pleasure, I enjoyed putting it together.
Unfortunately I only have DAK, but am eagerly awaiting the reprint of Burma...

Thanks so much, clarified a few things for me. Just a couple questions/

If this was an actual game, do you think the Commonwealth would be able to pull this off with so little supply left near the front?

What is the best way to get teh supply closer to the front in this scenario as the commonwealth?

Jim, many thanks for this!

I haven't even opened my DAK game, but I have a feeling this detailed and thouroughly illustrated example of play will come in very handy in the future. Plus it makes for a very entertaining reading!

Thanks, again, so much!