Megagame Designing – The Odds On and Off – Part 1

A Megagame may be about communication and conflict… however you can’t have Conflict without some way to resolve it (without resolving to actually killing each other).

Normally the result is a test with the result being enforced by the control team.

The majority of tests involve probability and as I’m currently looking at test mechanics, I’m looking at how probability can affect a Megagame and actually make it more interesting.



Roll against “x”… 3 words that makes any RPG player go weak at the knees.  Fate decides whether or not you succeed or fail.

As I was designing for my Megagame, I needed a simple test that was easy to explain.

In the end I used a target system where the players roll a number of dice where for every die where they equal or beat the target value, they gain a success.

For one example:


When players take any form of life threatening risk they roll 3 six sided dice:

  • 2 or 3 Successes prevents any injury.
  • 1 Success prevents death but not injury.
  • 0 Successes results in the death of a hero.

Below is the table of targets (1 is a fail on all dice tests) for three dice and the probability it will occur.

 Successes (Left)

Target (Below)







6+ 57.87% 34.72% 7.41%
5+ 29.63% 44.44% 25.93%
4+ 12.50% 37.50% 50.00%
3+ 3.70% 22.22% 74.07%
2+ 0.46% 6.94% 92.59%

So why am I mentioning this?  Well lets meet two people we will call the “Jammy Roller” and the “Cursed Roller”.

A single side of a die has a 16.67% chance of rolling; the Jammy Roller seems to roll 6’s 50%+ of the time and the Cursed Roller seems to roll 1’s 50%+ of the time.

A cold reality of probability is that it is a theory; if you roll a dice 6 times you expect to roll 1 through 6 once each.

The trouble is if you roll a 6 three times in a row… the probability of rolling 6 again is still 16.67%, it doesn’t decrease because you’ve rolled 6 before.  As such you can roll 6, 6 times out of 6, the probability of it happening being:


Rare but not impossible.

In context it’s possible for the factions in question to have two separate results; one factions keeping 100% of their starting units and one side being nearly wiped out.

This is actually a real design problem; how do you handle the reality of luck, when the Odds are On and Off?

Actually I’m not far away from the answer… because of the three words every RPG player are scared of…

… because we actually don’t hate them.

Every success and failure in theory should create a new challenge.  You succeed in discovering a trap… well done NOW get past it!  OR you trigger the same trap, now disarm it before it kills you!  Two different challenges based on the outcome of a single roll.

So back to the original issue of the test for this Megagame design.  What happens if the factions are controlled by Jammy Roller and Cursed Roller.

Jammy Roller gets more Recruits and they survive more quests and tasks so they will eventually reach the faction limits; however the GM* and his control team will spot the size of the faction and the antagonists will react and place more pressure on Jammy Roller because he can take it.

The challenge then becomes, how to manage the demands of everyone around you now they know you can take more of the load.

Cursed Roller will unfortunately gain fewer recruits and take more casualties.

The challenge then becomes rebuilding a faction destroyed which is a completely different challenge just created by a few failed rolls.

Even so, this doesn’t mean that you don’t prepare for them and be ready to take the sting off them… which because I’m well beyond 500 words will cover another time.