Tuesday, July 07, 2020

ACW rules - my One Hour Wargames derivative..

A couple of people have expressed an interest in the OHW rules derivative I'm using for the American Civil War project..  a couple of people equates to a 'groundswell' round here, so who am I to disappoint...

The following came out of a first game using them "as is" and a couple of interim versions to the one that I'm now using which have been pretty stable for almost 3 years now...

As in the original version of the rules these are vaguely brigade level as the way the rules teat terrain is pretty abstract, and basically models what your brigadier would be worried about rather than your average platoon sergeant..  so "walls" don't exist either as a terrain modifier, or a firing/combat modifier - they are assumed to be too small a terrain feature to be worried about and are just factored into the movement/firing/combat by assumption..

So taking the rules as is....
  • Basing - any way you like, there isn't really even a requirement for both sides to be the same, but similar is more aesthetically pleasing. I have used the basing/organisation that is now standard for my projects - in my mind I just imagine them as brigades rather than regiments...  all casualties counts are by roster and there is no base removal...
  • The sequence of play is abandoned/ignored and replaced by a dice driven initiative - throw a number of dice equal to the number of units, it is better to have a specific colour for each side, then assign the dice to each unit - the bigger the number the sooner they activate. Each unit is then activated according to the assigned dice - this gives a pleasing friction to the game, the commander is forced to decide where his tactical pain points are, and also where he needs to defend and assign the dice accordingly.
    • Optional rule #1: dice to see which side has the initiative, and the loser assigns their dice first so that the winner has a view as to where and what dice have been assigned. 
    • Optional rule #2: throw a number of dice equal to the number of units and each commander takes it in turn to take a dice from the pile until they are all used. 
    • Optional rule #3: good commanders can add a dice (or more), allowing the worst one (or more) to be discarded..  
    • .. etc etc
  • If two opposed units have the same activation dice, and the order in which they activate is important (ie. one wants to fire before the other, or withdraw out of range before the other fires, or whatever...)  the two units take their dice and throw again with the higher number going first
  • When the unit is activated it can either move or fire or charge or do nothing. 
Movement as per the rules but:
    • We added a march column value for each troop type that is 33%/third greater
    • We split cavalry into mounted and dismounted - dismounted movement is the same as infantry
    • Formation changes - because we added the column speed there has to be a cost for changing between line and column (limbered/unlimbered for artillery) and that is movement less 2" for all troops types except cavalry dismounting and artillery limbering/unlimbering which is movement less 4"
    • Interpenetration we allowed for all troop types but at a cost equal to a formation change to represent the disruption, and only if both units have an activation dice unused..
    • Terrain:
      • Woods : because we have a dismounted cavalry type they are also allowed, and we added a one third movement penalty for all
      • Towns: because we have a dismounted cavalry type they are also allowed, we also added a formation change cost to enter/leave a town for all.. 
      • Marsh/Lakes unchanged
      • Rivers unchanged but fords/bridges can be crossed "in march column only"
Charging - Thomas doesn't allow for melee, but while we agree it was rare, DG and I also believed that we needed to model it if only to given a reason for the "Rebel Yell"..     So the following section is largely ours, but in the spirit of the rules...

  • Artillery cannot Charge full stop - seems obvious, but hey...
  • A unit cannot charge if it is in march column
  • Mounted Cavalry can Charge any unit
  • Infantry, Zouaves, Dismounted Cavalry must have an “advantage” over the Target in order to Charge; which is either 
    • attacking vs Flank or Rear, or 
    • 5+ strength points advantage over the defender
  • Target of the charge is permitted to fire first if it hasn't activated already - rules are as per normal firing - remove the activation dice after firing
  • A target in march column is automatically eliminated on contact
  • An Artillery target is automatically eliminated on contact 
  • Charge movement is as per normal line movement, and has to end in contact
  • Turning is as per the movement rules but with the exception it can only happen at the beginning of the move..
  • No changing formation can be done as part of the Charge
  • No Interpenetration when Charging - and if there is any retreat and you have to interpenetrate to do it then each unit takes a 1pt damage
  • Terrain effects as per normal movement 
  • Melee
    • Only the Charging unit inflicts casualties 
    • It rolls a D6 and modifies the result as follows, and incrementally 
      • Charging +2
      • Zouaves +1
      • Dismounted Cavalry - 1
      • Defender outnumbered by <= 15 points +2; <= 10 points +1;<= 05 points +0
    • Then, halve the end result if the defender is either uphill, or mounted cavalry, or in towns/woods
    • Then, if the attack is in flank or rear multiply that result by 2
    • Round fractions down
    • If Defender is not eliminated the Attacker retreats straight back [facing defender] - Mounted Cavalry retreats 6”; others 3”
    Firing as per the rules with the addition/exception of
    • March columns cannot fire
    • Units must be on the edge of cover to fire out of it
    • Units firing within cover have a range of 3”
    • We added a short/medium/long range with relevant modifiers
    • We added a section for handling firing when the target of a charge (basically you add/subtract the difference of the activation dice)
    • We added some modifiers to reflect the remaining strength of the unit
    Casualties: once you get to 15 the unit is removed..

    In summary then, a bit more detail, a new section to cover melee, and the activation dice...


    1. Hello old chap,

      These look eminently usable so I will give them a spin at some point. I also fully approve of using Kurz and Allison prints to illustrate the post!

      I hope all is well with you and yours,

      All the best,


      1. Greetings old fruit... thought you might like those reminders of your own little project... if it makes it easier, consolidated set here: https://steve-the-wargamer.webs.com/ACW/One%20Hour%20Wargame%20ACW%20v2.DOCX

    2. Interesting ideas there Steve, thanks for taking the time to type it all out.

    3. David - no problem - if you fancy a consolidated set, I have put a link to them in the reply to David C. just above..

    4. Good mods. I very much agree with the ‘charge’ especially when it is framed in one side simply trying to impose itself on the other (my closer fire, intimidation and running at the enemy) and not necessarily always a bayonet charge to contact in the full sense of ‘charge’.

      The ACW rules suffer a bit from the phases being separated into move first and then fire, as it does not give a chance for units to take ground after fire, especially if it has been decisive. Do your mods mix up the fire and movement into a joint phase (i.e. a unit just chooses which one it wants to do) or are the activations still split, do that all movement happens first and then all fires?

      1. Hi Norm - it seemed like it made sense to have the melee a one sided affair in the same way as firing is... I guess if we wanted to we could use the DBN mechanic and have both sides participate but only the attacker inflict casualties if he has a better result than the defender? This way is simpler which fits the ethos better I think... With regard to sequence, yes, the dice mix it up big time... you can do any of the actions you want, but decided by the dice results...

    5. Very interesting. Thanks for taking the time to put these on Steve - they should be useful for solo games, which as you have discovered needn't be without challenges. Stay well. Jim

      1. Thanks Jim - as you know - the older I get the simpler I like the rules, but whilst still trying the best I can to stick to period flavour... I think these are a good compromise.. I really like the dice mechanic, I may well retro fit that to some of the other rules I have as well as it makes a good solo mechanic..

    6. An interesting morning read Steve, thanks for taking the time to share them.