OCS early days -prior to V 4.0


Kiraly posts his thoughts on the original OCS title, Guderian Blitzkrieg, and where it contrasts to the current v4.0 rules, thanks for letting me share this Kiraly. Oh and note all images are from BGG Game folder. An interesting read overall, and one that will have me looking for his play notes when he final does it.

I didn’t start playing OCS until a few years back, and even though my collection includes all of the games in the series, I have never played any of them using anything other than the current version of the system rules (hereafter referred to as “v4.0”). While I’ve never really had any issues playing older games with v4.0, there have been some discussions on CSW and BGG on how to make some of the older games work properly with them.

It appears to be generally accepted that all of the games in the series can be retrofitted fairly easily with the exception of one: Guderian’s Blitzkrieg.

Rob Bottos, in his younger days! Playing GB.

Being curious as to why this is I’ve decided to take a brief look at the original Operational Combat Series’ rules (hereafter referred to as “v1.0”) and see what the major differences are. Whenever reading the rules to a wargame I’ve never played before, I always like to start with the Sequence of Play, to get a feel for how the game flows.

In v1.0 it is important to remember that turns represent an entire week of operations as opposed to the half-week (or quarter weeks in Sicily) in v4.0. 

Sequence of Play

The Sequence of Play starts with what is called the Overphase, v1.0’s version of v4.0’s Pre-Turn Phase, and contains the following segments:

1. Weather Determination Segment
2. Supply Usage Segment
3. Reinforcement Placement Segment
4. Replacement Reorganization Segment
5. First Player Determination Segment

The Weather and First Player Determination Segments look familiar enough, with the only real difference appearing to be that only a single die is rolled per player in the First Player Determination Segment under v1.0.

This appears to have changed sometime between v1.0 and v2.0i. I’m not sure why this would make any difference, but I’m sure there’s a reason for it, even if it was just a personal preference of those writing the rule.

The Reinforcement Placement Segment is played simultaneously with both players rolling for and placing variable reinforcements, and placing scheduled reinforcements, newly available SPs, and air units on the board. This is a big difference from v4.0 where they are handled in the Reinforcement Phase of each players’ Player Turn and not simultaneously.

While in v4.0 players handle any reorganizations, rebuilds, and consolidations in their own Reinforcement Phase, in v1.0 these types of activities are handled simultaneously in the Replacement Reorganization Segment.

There are several other activities that can be taken care of in this segment that will look out of place to those of us who’ve only played under v4.0, including construction type activities and the generation of breakdown units.

Finally, the most obvious difference found in the Overphase is the Supply Usage Segment. In this segment supply is spent based on Divisional Supply Equivalents (DSEs) to support upcoming operations for the turn and to determine the “usable level” of each airbase. I’ll take a little more detailed look into supply concerns under v1.0 in a bit, but peeking ahead at the Sequence of Play one will find that there is no Supply Phase. The concept of trace supply does not exists here, meaning that in order for your units to remain supplied they have to use actual SPs during the Supply Usage Segment.

Other than the Supply Usage Segment and the order in which certain activities take place, there doesn’t appear to be anything in the Overphase that newer OCS players shouldn’t already be familiar with.

Continuing on with the Sequence of Play there are two Player Turns, each consisting of:

1. Air Unit Return
2. Air Unit Refit
3. Mode Determination
4. Movement
5. Reaction
a. Movement Segment
b. Barrage Segment
c. Combat Segment
6. Combat
a. Barrage Segment
b. Combat Segment
7. Exploitation
a. Movement Segment
b. Barrage Segment
c. Combat Segment
8. Cleanup

Other than the missing Supply and Reinforcement Segments which are handled in the Overphase, the sequence here should look pretty familiar. One thing that did jump out in this sequence, however, was the Combat Segment in the Reaction Phase. In v4.0 the Reaction Phase consists of just movement followed by barrage, so the only possible combat during that phase would consist of overruns. The ability to throw in an extra round of combat during reaction could lead to some very interesting situations.

Another major difference is that the Mode Determination Phase occurs before the Movement Phase. According to v1.0 all voluntary mode changes must occur in this phase before any movement occurs.

This is a big difference from v4.0 where mode changes can occur during the Movement Phase as a unit begins its movement. This is one of those rules were I would be very forgiving to any opponent who forgot to change the mode of a unit or two during the Mode Determination Phase. Of course Dean and company appeared to realize what a pain in the ass this could be and provided an optional rule to handle mode changes as they’re handled in v4.0, stating in the designer notes that this optional rule was used exclusively during playtesting.

For the most part the various Combat Segments appears to work the same although there are a few noticeable differences such as:

The much debated Surprise rule is optional. 
Combat and Barrage costs are much cheaper.
An attacker can declare an At All Costs Attack.
Anti-Overrun Barrage Attack capability.

The Air Unit Return Phase is also something not found in v4.0, and looking through v1.0 it appears that outlining the differences in the air rules between the the two versions would make for an excellent post of its own sometime in the future. For now I’ll just say that the differences appear to be major and well worth exploring if you’re looking for a bit more detail than what v4.0 has to offer.


As mentioned above there is no trace supply in v1.0. Units must be supplied at the beginning of the turn during the Supply Usage Segment using available on map supply. Each player determines the Divisional Supply Equivalents (DSEs) that need to be supplied for each Drawing Group, a Drawing Group consisting of any number of units that are being supplied by a single HQ or single supply dump. Once the Drawing Groups have been determined players can choose the Level of Supply that they would like each group to be assigned.

If you’re willing to pay 1SP per DSE the group is in Full Supply and has full capabilities. If you’re only willing, or only able, to spend 2T per DSE then the group is in Low Supply and all of the units within the group suffer halving of any attack or barrage values they may have. Finally, if you’re unable to spend at least 2T per DSE then the group is Out of Supply and all units suffer the consequences including having to roll on the dreaded attrition table.

Players do not have the option to put a group Out of Supply voluntarily. Any available supply, even if it is not enough to put the group into Low Supply, must be spent in an attempt to bring the group up to at least Low Supply.

I’d imagine it would be very painful to be just short of the 2T per DSE needed for a group just to see all of that supply go away and still have the entire group marked Out of Supply. Another thing to remember is that the Supply Usage Segment occurs at the very beginning of the turn, so it is very important to keep pushing the supply forward so that large portions of your army don’t find themselves with out it when when setting Supply Levels.

DSEs are determined by unit type, with non-motorized divisions counting as a single DSE while an armor or mechanized unit (regardless of size) and fully motorized divisions count as two. The cost of 2SP to put a single armored battalion in full supply seems like an awful lot to those of us used to v4.0 but I’d imagine this is offset a bit by increased supply availability, decreased combat costs and the fact that once a unit is put into Full or Low Supply there is no need to expend any SP to fuel them.

Other than the Supply Usage Segment, the way supply is used and transported doesn’t appear to differ much between v1.0 and v4.0. One interesting difference, however, is that the “adjacent is good enough” rule appears to only be in effect when an HQ is throwing supply to units during the Supply Usage Segment and is not allowed when drawing combat supply.

Closing Thoughts

After completing my initial look into v1.0 I’ve made it one of my gaming goals to play Guderian’s Blitzkrieg using the original rules just to to see what it’s like. I’m very intrigued by the idea of having to carry all necessary supplies forward as opposed to relying on an abstracted trace supply to keep my units in good supply status. I’d imagine the threat of being cut off carries a little bit more weight when getting units back into supply involves both opening up a supply route and moving supply along that route to the newly liberated units. Simply opening up a supply line isn’t enough to do the job.

Finally, I have not given v1.0 a proper detailed reading, instead focusing on the areas that I felt were different enough to be interesting. That stated, there may very well be some things that I’ve addressed that I have misunderstood to some degree. My hope is that these misunderstandings will be corrected in time by both those who have played using v1.0 and my own experiences learning and playing the Original OCS.

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