ACWCO Engineering Department

ACWCO Engineering Dept.


Robert Frost's Enhanced HPS/JTS Files

Those of you who played the old Talonsoft Battlefround games probably know Robert Frost as part of the Norris/Frost team that created a modified version of the game that was pretty popular with those who preferred a more 'historical' mode of play. The lower stacking limits, strength factor modification and fire combat results changes rewarded players who used a more historic style of play. The reduced effectiveness of melee due to the lower stacking rewarded the player who used a more linear style of fighting rather than making large stacks to melee and charging forward.

When the HPS system came out Robert did some studies on it and provided some recommendations for pdt file changes. I used his HPS pdt file which was modified mostly for changes to artillery ranges and effectiveness because it agreed with my own studies of the use of ACW artillery, in the moderated games I ran about 10 years ago. I still use his algorithm for calculating small arms ammo whenever I create my own scenarios.
After what appears to be a pretty intensive study he has released his most recent work on the HPS system . From what I've seen in my initial study he has done extensive research into such things as march rates and casualty rates and his explanation of his reasoning for his changes makes sense to me.

At this point I have not been able to do much testing of his work but having been asked to provide a place where it can be accessed by ACWGC members I have placed the files here at the Engineering Site along with a brief explanation of the various files.

You can download each file individually by clicking on the bold link or you can download a zipfile containing all of them  Here.

Use the Navigation links to return to this page.

Read This First.pdf

This is a brief explanation of the files.

Enhanced Movement.pdf

This pdf file covers the reasoning behind the Movement rate changes.

Movement Parameters.pdf

Just as it states this is a list of the various movement costs for Robert's system along with some notes on possible changes for some terrain due to the differences in the terrain on various battlefields.

A Rifle Value of 3.pdf

An explanation of the reasoning for reducing the Rifle Musket Range to 3 hexes, including several historical writings that validate the reduction.

AI Opportunity Fire.pdf

A fairly extensive report on Robert's tests of the Turn Based Opportunity Fire and his reasoning for changing the pdt to improve the effectiveness of Opportuity Fire when it is initiated.

The pdt files listed below will be displayed on your browser. If you wish to download them you will need to go to the Enhanced link below.

Enhanced Standard20.pdt

Robert's modified pdt file for the standard 20 minute daylight turns. This file contains his modified movement rates and combat factors which includes range and effectiveness changes.

Enhanced Standard30.pdt

This file is similar to the Standard20 but movement factor and combat values are modified for 30 minute daylight turns

Enhanced Turn20.pdt

This file contains the same movement factors as the Standard20 file but has additional changes in the combat factors designed to improve the Opportunity Fire effectiveness.
As I understand it this will not increase the frequency of Opportunity Fire as that is in the game engine itself, but should increase the effectiveness of Opportunity Fire when the AI calls for it.
This pdt should be used only for Turn Play along with Robert's suggestion of all units being moved individually, no stacked movement, thus providing more chances for Opportunity Fire to be initiated.

Enhanced Turn30.pdt

Similar to the Enhanced Turn20 file above but this one is modified for 30 minute daylight turns


This is a zipfile containing all of the above files for those of you who prefer to store them that way.

Robert Frost's Ammunition Algorithm

This is a zipfile containing Robert's Ammunition Algorithm. It includes both a Microsoft Word .doc and a plain .txt file.


Notes on using these files.

The .pdt files available here were created from the Gettysburg game. You do not want to just plug them into any game or use them to replace the standard pdt files for your game.
The table below lists the lines you will most likely need to change.

Line 1: Version number (1 through 8) you will want to match the version shown in the stock pdt files.
June 1863
Line 2: Normally Game Title, once again it would be best to match with line from stock pdt.
Line 3: First side (0 = Union, 1 = Confederate) once again match the original pdt
4 0 21 0 1 4
Line 4:
Dawn hour - 4
Dawn minute - 0
Night hour - 20
Night minute - 0
Hours of twilight - 1
Twilight visibility - 4 (if negative, causes poor weather message).
Once again you want to match the original pdt values here.
20 60
Line 5: From this point until Line 96 you will want to use the values in Robert's pdt unless you are familar with the pdt file and wish to change them. You can look at the "PDT Files Explaned" page on this site for more information on the rest of the lines.
Line 96: If version >= 5, night movement fatigue.
This is the last line of Robert's pdt's. If your game has a pdt version > 5, (Line 1) you may want to consider adding the following lines.
Line 97: If version >= 7
120 Crew Kill Level - refers to the number needed to produce a Crew Killed result. Default Value is 100, higher values mean fewer crew kills, lower value means more crew kills.
Line 98: If version >= 8
This is from the new game Overland and only used there currently.
Trench Value - refers to the number needed to produce a Trench in a hex. This value is built turn by turn using the formula number of men / 100 x number of turns.
1 1861 7 18 9 0 100 6 135 90 -10 0 Heavy mist
Line 99 until 0: If version >= 5
Weather Lines - If you wish to have weather you can copy the values in the game pdt you are replacing or write your own using the "PDT Files Explaned" page on this site
End of Weather Lines - 0 Indicates the end of the pdt file.


If you want to play a scenario to try these files here is a suggested step by step procedure.
1. Use a text editor to modify the Enhanced pdt to match the game you are going to play as noted above. I suggest saving the file as pdt name_20E.pdt or pdt name_30ET.pdt or something along those lines.
2. Use the Scenario Editor to open the game file you wish to play, and save it under a similar name. See the "Using the Scenario Editor" page for an explanation of how to do this step as well as adding to the scenario description to note the use of a modified pdt.
3. Change the name of the pdt file in the .scn file, once again see the "Using the Scenario Editor" page for an explanation of how to do this step.
4. Open the scenario using the game engine, set optional rules and sides and make your first move.
5. Email your opponent the game file and the pdt file, he will need both or he will get an error when he tries to open your game file. He will not need the modified .scn file to play but you can send it if you want. Once the game file is created all info from the scn file is copied to it. However both the .map file and the .pdt need to be in the game's main folder so you will need to send the modified pdt file.

Questions or Comments can be sent to the email listed below.


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Page designed and maintained by Ken Miller
Last updated 01/18/2018

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