OCS Assistant 1.0


This nifty tool is an odds calculator for the OCS 4.0 CRT and Barrage Tables. Enter the Combat Factors and Action Ratings of the attacker and defender, manually modified for any applicable DG, terrain, OoS, or other circumstances. Put in some other values (hedgehog level, terrain and whether this combat is a regular combat or an overrun) and view the odds for different outcomes in the list below. The odds are adjusted for possible defender/attacker surprise shifts.

Screenshot of the Mac version of OCS Assistant

Interpreting the results

The cryptical text just below the terrain combo box (4:1 (A27%/D41%) in the screen shot) tells you on what odds column to resolve the combat, and the chances for getting an attacker or defender surprise. The probability for getting a surprise in the example above is 27% for attacker surprise, and 41% for defender surprise. The calculation of the combat ratio to use is adjusted per the rules and the CRT from version 4.0. If you for example input 12.25 combat factors vs. 3.66, this string tells you to resolve the combat on the 3:1 column, taking all the OCS rounding rules into consideration. And if you enter 100 vs. 10 combat factors using the terrain type Extremly Close, you'll be directed to use the 8:1 column, since there is no 10:1 column for that terrain. (And you also realize that you just comitted 25 combat factors for nothing...)

The list below the entry area should be self-explanatory (it shows you the odds for every possible result). Select multiple rows in the table to see the accumulated odds for acheiving any selected result. Just below the box (Losses) you can see the odds for getting at least a 1 step loss on the attacking or defending side.

Screenshot of the Windows version of OCS Assistant

The second page of the application (click Barrage) is a simple calculation of the odds for the different possible results from an attack on the barrage table. Input the barrage factors (manually modified for target density, terrain, etc), check the box if your target is in a lvl 3 hedgehog, if you don't have a valid spotter or if ship or air fires (see the barrage table and the rules for more on this), and check out the odds in the list below.


This tool is freeware. If you have any comments, feel free to contact the author using the messaging feature of BoardGameGeek, username: MatGot.


  • Download Mac OS X 10.6 version by clicking here
  • Download Windows version by clicking here

There's also a web version, for use with mobile phones and similar. Available at this location: http://tanner.tanto-system.se/ocs/ocs.php