This is a guest post on from Jonathan Tweet, who is in the last 24 hours of his Over the Edge Kickstarter with Atlas Games. I didn't directly contribute to the design of Over the Edge, but it turns out that I contributed indirectly!
Rob’s first professional appearance at Wizards of the Coast was when he in brought an interesting skirmish miniatures game and showed it to leads in the game design group as a possible acquisition. It was designed as a Glorantha game, but it would work the same way for a Magic-based miniatures game. The special dice you rolled mostly had numbers on them, but some faces instead had runes that triggered special abilities. When you rolled the dice in this game, the numbers you rolled were important, but so were the runes.
He brought the same approach to 13th Age, where a monster’s attack roll determines not only if it hits but also whether something else happens. For example, if a phase spider hits you with a d20 roll that’s even, it can make a second attack to steal one of your magic items. The attack roll means more than simply hitting or missing, and the gamemaster can use the same attack over and over with different results from round to round.
The original Over the Edge from 1992 had a linear dice mechanic, where your roll of multiple dice resulted in a number that indicated how well you had performed the task being attempted. The new Over the Edge has a linear scale on two dice to determine success or failure, and it adds good twists (if a die is a 4) and bad twists (if a die is a 3). These are the surprising results, good or bad, that are part of the conflict’s resolution. The good twist and bad twist rule was the original concept that the whole dice rolling system is based on. That approach derives directly from Rob’s dice systems that provided results that were different not just in quantity or degree but in quality.
The Kickstarter for the new Over the Edge ends Pacific.