Tuesday 29 June 2021

‘O’ Group - looking at the gun / armour system



‘O’ Group are David Brown's most recent set of rules (he is also designer of Pickett’s Charge and General d' Armee rules), covering World War Two. Published by Reisswitz Press (a publishing arm of the Lardies), the rules cover action at the battalion level. That is, a typical game would see two to three infantry companies per side, plus assets.

Each infantry base represents a section, they are gathered together to make the basic manoeuvre unit - the platoon. Interestingly, each armoured model is representing 2 - 3 vehicles and is referred to as a section, with two sections forming a typical platoon.

As armour is my primary interest, this was the first part of the rules that I turned to and the rest of this post is going to give way to discussing the gun / armour relationships in the game and the processes that fall out of a typical little vehicle duel.

Please use the ‘read more’ tab for the rest of this post.


Obviously, it is the full package that is important, with the rules working as an integrated whole, but I can’t help myself turning to the ‘anti-tank’ section first and poring over the gun charts and relative armour and gun values.

Pre-purchase, I had thought the game was intended for the smaller scales, so was surprised to see the rules giving two sets of measurements throughout, one for 15mm and smaller and the other for 20mm and above, making it easier to use and avoiding the need for mental conversion of measurements, regardless of what figure scale you choose to use.

At the start of each turn, both sides roll dice to see how many orders they get and then the question of initiative is determined. For the sake of our example, we will assume that our action is an important point of decision on the battlefield and that everything is sufficiently and properly resourced with orders, but we will test initiative along the way.

For our mini gun duel and slice of action, we have a German Tiger I tank taking cover amongst a hedged orchard. Approaching are two Sherman 76mm vehicles in the open. Although there are just two Sherman model tanks in play, we should think of them as representing a full strength 5 tank platoon, with say one vehicle representing 3 tanks and the other 2.



The Tiger model likewise would represent a section of a couple of vehicles in the game, but I don’t want that. I would prefer to think of this as a lone vehicle fending off a U.S. platoon. So to do that, we will start with the Tiger tank having a damage marker already placed on it. This will help represent the section being reduced to a single vehicle.

At this point, it might be worth the reader pausing a moment and deciding in their own mind how they think this mini gun duel should play out and end. Will the Tiger survive? Will the Shermans be stopped in their tracks? Do you have stereo-types of this sort of action?

In the game, a Damage result is interpreted as one of the vehicles in the section getting damaged, a second damage result will see the full tank section Knocked Out and the model marked as KO.

At the start, we will set the Shermans 21 and 23 inches respectively away from the Tiger.

I am using the 20mm scale. In this scale, vehicles have a standard gun range of 40” (30” for 15mm and smaller). Tanks can fire further, but they must be on elevated ground, no matter how slight, so seeking out undulations might become important in some games.



In my test game, there is high ground located around 15” behind the Tiger’s position, which would be a good position for their powerful gun to dominate from, but they have chosen the orchard as their defensive position.



It is always interesting to look at the gun / armour relationships that designers have settled upon.

Here we can see that the Panther and Tiger are very similar, but with the Tiger having heavier side armour. The low velocity 152mm gun in terms of actual damage capability, is performing like the high performance German Tiger and Panther weapons, due no doubt to the weight of that colossal shell hitting a target and the U.S. 76mm is performing at the same gun value as the German 75/48 (not shown here) and the upgraded T-34’s 85mm gun (also not shown here).

All of those values sit in a range that look to be in a reasonable relationship with each other, especially having regard for actual penetrating effect being further influenced by the randomising effect of 2D6, which have a Bell Curve effect on outcomes.

Two good things initially strike me about the anti armour system, it is based around credible maths and the process is smooth and easy to apply.

One final note, we must talk about spotting. As soon as you see the word ‘spotting’ in rules, there is every chance of tedium and trying to remember who has spotted who etc …… but not here!

If the target is in the open, then it is spotted. If it is in any type of cover, then at the time of firing, a different coloured D6 is also rolled and this is the spotting dice. On a 1 - 3 the target will be spotted, on a 4 - 6 it will count as obscured.

Where this matters is on the Damage Table. It has two rows, a spotted row and an obscured row, you simply roll on the appropriate row that the spotting dice determines …. Simple, yes. It manages to get cover and spotting all into one straight forward roll and it is ALWAYS done, even if you spotted or hit the target last turn, so no need to remember who hit who. I do like this rule. 

The Action!

In our first turn, we will assume that the Germans have won the initiative. This allows them to take the first part of the turn, so they will fire first.



Firstly the Tiger must hit the target, so rolls 2D6 to do that. The ‘To Hit’ process always needs 7 or more to hit (after modifiers, such as firer moving or suffering shock or damage etc). It does not roll the spotting dice on this occasion, because the Shermans are in the open. It applies a penalty of -1 to the 2D6 for being damaged.

It misses!

The target is allowed to immediately fire back, but requires an order being spent on it to do so, we shall definitely do that.

First the Sherman must pass a ‘To Hit’ roll. The Tiger is amongst cover, so a spotting 1D6 is also rolled this time and so the Tiger may or may not be obscured. A different coloured D6 for spotting is rolled at the same time as the 2D6 for the ‘To Hit’. The Sherman ‘To Hit’ roll misses. As an aside, the spotting dice is successful, not that it matters in this instance as the target is not hit.

That concludes the Tiger’s actions, so assuming that the rest of the German forces over the rest of the table have concluded their part of the turn, play now switches over to the Allied player.

What to do? The decision is to fire with both Shermans and not to move them. You can move and fire, but the fire gets a penalty.

The first Sherman fires and misses. This allows the Tiger to immediately fire back at the Sherman.

So in this game, the tanks get a chance to fire twice during a full turn, once in their own Action Phase and also once as response to incoming fire during the enemy Action Phase, though each firing requires the expenditure of a separate order. A player will be unlikely to have enough orders available to fire many things twice per turn in a full game.

It is still the Allied Action Phase, but the Tiger spends an order and responds to the fire, firing back and hitting the Sherman (rolls an 8. Anything that is 7 or more is a hit), so we move to the Damage Table.

The Tiger has a gun value of 11 and the Sherman has a frontal armour value of 7. Taken as a differential, this gives the Tiger a significant difference of 4 to their advantage. They roll 2D6 on the Damage Table, getting 8 and then deduct that 4 (the differential) from the 8 …. giving a final result of 4 (the lower the better).

So anti-tank combat is essentially based around the difference between the gun and the armour and this difference acts as a modifier on the Damage table.

We ignore the ‘Obscured’ line on the Damage Table and look at the ‘Spotted’ line on the chart, as the Sherman is in the open and automatically spotted. The Table shows that a score of 4 or less is a straight Knock Out. Other results from a higher dice roll could have been Damaged, Shocked or No effect.



The KO against the model is representing the destruction of 2 - 3 tanks. The model stays on the table, but is marked as being destroyed.

“Oh Dear” says the remaining Sherman commander. It is still the Allied player turn and an order is placed on the remaining Sherman to fire. It scores a hit and also rolls a successful spotting dice, so we go straight to the Damage Table and roll on the ‘spotted’ row.  

The Sherman 76 has a gun value of 9, set against the Tiger’s armour value of 11, so the attack is made with a difference of 2 in the German favour. This will add +2 (bad) to the Allied dice roll. They roll high at 10 (Oh No!), which the +2 modifies to 12.

A score of 9 or more is no effect. If we pretend for a moment that we had rolled say 4 (+2 differential) to give 6 and the Tiger was successfully 'spotted', then the result would have been 'Damage' and since the Tiger is already damaged, that would have been converted to a Knock-Out. Even a roll of 6 (+2 differential) to give 8, would have put shock on the Tiger, so the 76mm gun does have some potential to harm the Tiger.

That is the Shermans done for this turn, once all Allied units on the table have concluded their turn, the turn will end and a new one will start, with both sides creating new order allowances and testing for initiative.

The Allied player must think now. What is the best thing to do? The odds are now very much stacked against them. They decide that reversing into the small wood behind them is a good idea, but first, Initiative needs to be established.

But it is the Germans who win the Initiative, so they will get to go first and will spend an order to fire against the remaining Sherman, before the Sherman can spend an order to move. 

Kaboom! A hit and a Knock Out, the Sherman is smokin', so that is the end of that!

Well, that rather fitted my own stereo-typical view on the likely outcome for Shermans going head on against a heavy tank in cover, though with the right dice (a bit of Lady Luck), either side could have dealt out some shock or damage results, which brings tactical nuance and flavour to the game, it’s just that the rolls in our test game didn’t bring any of that out.

The damage result represents one of the vehicles within the section getting damaged, which would then cause a -1 To Hit modifier on the tank’s future firing, plus a second damage result would destroy the tank section.

Shock is more nuanced. The Damage Table can generate either 1 or 2 shock and this can accumulate, building up on the vehicle. It also causes the ‘To Hit’ dice to be modified by -1 (bad).

An AFV can absorb 3 shock, but at that stage it goes Suppressed (can’t fire or move without a Rally or Withdraw Action). Once suppressed, a further 2 shock will cause a KO, so there is a downward spiral of effect with accumulated shock.

Units can spend orders to attempt to Rally shock off and this will become important as the shock results gather.

In our test game, the two Shermans might have been lucky enough to inflict some shock onto the Tiger if they had rolled 6 or less on the damage table, not a desperately hard thing to do and you have two barrels attempting that, but a frontal engagement against a heavy tank is still pretty fraught, as it should be.

If the Shermans could manoeuvre and drop onto the Tiger’s flank, the Tiger’s armour value drops from 11 to 8 and that becomes a much more attractive proposition for the decent 76mm gun on the Sherman and we must also remember, many engagements will be against the more common Panzer IV’s and StuG III’s, putting the Shermans on a much more even footing.

We chose the Tiger / Sherman match-up here to deliberately bring together contrasting values.

The Shermans are classed as an average vehicle for movement purposes and so can move 2D6 + 2” over open terrain, so it would take them a couple of turns at least to get into flanking positions, but if they could also get the range to the Tiger down to 15” or less, they would be able to claim ‘Close Range’ when firing, which helps both the ‘To Hit’ die roll and tank fire value by +1. 

Since that would help both the Tiger and the Shermans, the initiative and who fires first might become the critically important factor. 

But WAIT! What’s this!

We have suddenly been transferred to the eastern front and one of those S.U. 152 ‘Beasts’ has shown up! With an armour value of 8, it is not so well defended, but a gun value of 11 gives the Tiger something to think about.



The S.U. fires - it hits - it spots. 11 gun value Vs 11 armour value gives a zero differential, so no modifier. A roll of 8 or less will do something. They roll a …….. 5! which results in damage, usually it takes a second damage result to destroy the section, but remember, we started this scenario with the Tiger already damaged to represent a lone vehicle, so therefore in this instance the Tiger is destroyed.

Had it survived, The Tiger’s return fire would have been gun value 11 against armour value 8, giving -3 modifier on the Damage Table (in the German favour), so a raw 2D6 roll of 11 or 10 (minus 3), would cause shock, a raw 9 or 8 (minus 3) would cause damage and a raw 7 or less (minus 3) would be a KO - leaving it practically as vulnerable as the Shermans were and preserving the fearful reputation of the Tiger!

In all of my tactical games, regardless of the system, SU 152’s never seem to last for long! They have a powerful punch, but fairly weak armour by comparison, which makes nervous things want to pick on them.

Overall, my afternoon of tinkering with the gun / armour rules have left me pleased with the processes and outcomes. Once I get a full battlefield up and running and start to play a more integrated game, I can see this rule set delivering a lot of nuance and points of decision. 

Gun / armour rules have the potential to be quite complicated, but these are very streamlined, made more-so by the simplified spotting process and the results seem credible. I am pleased with my purchase.   

Resource Section.

EDIT - Rule support, including comprehensive vehicle and gun lists for ‘O’ Group LINK

http://generaldebrigade.blogspot.com/

‘O’ Group forum on the Lardies site LINK

https://toofatlardies.co.uk/forum/index.php

My sister webspace COMMANDERS is being re-configured to showcase various figure and boardgame systems that I am enjoying and give a flavour of where current ongoing projects are up to. Link.

https://commanders.simdif.com