Risk Dice Odds Calculator

The odds for regular board game Risk are well known, but newer versions of Risk add some new variations. This Windows program allows you to add bonus dice, 8-sided dice, or add to your highest roll. These variations are available in offical releases of Risk games like Risk: Reinvention and Star Wars Risk.

Download the file (44kb) by right-clicking the link and saving.

How to use Risk Dice Odds Calculator

By default, if you click on Run, you will get the odds for regular Risk dice rules of 3 attacking dice vs. 2 defending dice.

Bonus Dice In some variations of Risk, player can earn a bonus die allowing the attacker to roll 4 dice instead of 3 or the defenders to roll 3 dice instead of 2 (the defenders will still only have 2 troops at risk and throw out the lowest die roll). To add a bonus die to either side, just check the Use box.

Add to your highest roll Some versions of Risk allow the use airfields which add one to your highest roll either in attacking or defending. To enable this option, just type 1 in the box labelled "Add to Highest". You could add 2 or can also add 1 to your second highest roll. Since only two troops are involved in a battle, it doesn't do any good to add 1 to the third highest die.

8-sided dice To try out odds with an eight-sided die, just enter 8 in the High box. If you can use two 8-sided dice, enter 8 in two of the boxes.

No 1's Sometimes you get the ability to re-roll a die if you roll a 1. You can change the Low value to 2 on all of your dice, but that isn't exactly the same as re-rolling a 1 if you only get to re-roll one 1 instead of all 1's.

Screen Capture of Risk Odds Calculator


The program runs through every possible combination of dice when you click Run and gives results in the text box at the bottom. The first line shows how many different combinations of rolls are possible. The breakdown of the different battles is then shown, giving the number of times the attacker wins twice, the number of splits, and the number of times the defender wins twice (or attacker wins and defender wins if the defender choose to use only 1 die). Finally, in order to plan your battles, a number is given that tells you how many attackers will be lost in wiping out 100 defenders (on average, your actual results will vary).


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Last modified: November 28, 2012