The "Adjustment" Die

Rolling for Narrative Inspiration
The world's most popular game first published by TSR in 1974 uses a binary "succeed or fail" die roll mechanic. As an extension of wargames where the "succeed or fail" dichotomy was standard, the White Box mechanic set the standard for the new adventure game (role-playing) hobby games. But today there are other options. Two recent FRPG acquisitions have got me thinking about at least occasionally adding a die to determine something like degree of success, momentum or to introduce additional narrative elements such as boons and complications to our dice outcomes.

The Blackest of Deaths published last year by Bloat Games uses an additional d6 rolled with your to hit die (or alongside any d20 roll to succeed/fail) which is used to add narrative by the referee in the form of a possible benefit or hindrance. it's a simple mechanic where there is a 1-in-6 chance of something of benefit occurring as a result of the character action regardless of actual success or failure of the attempt. On the other hand, there is also a 1-in-6 chance of something that may hinder the character(s) occurring. 

Chivalry and Sorcery 5e delivered this year by Britannia Game Designs following their successful Kickstarter uses an additional d10 to determine degree of succeess. The "crit die" is rolled along with percentile (d100) dice and depending on whether the outcome is a success or a failure the "crit die" gives a value of 1-10 with a "10" being a critical. (Critical failure is akin to a fumble.) A success with a "crit die" score of "2" is less dramatic than with a "crit die" score of "3" or higher. It's a simple mechanic that can add to damage in a combat system or be used to add narrative in other situations.
The additional d6 or an additional d10 roll can be used with almost any binary outcome system to add an extra dimension to the random outcome. It seems a nice tool to add to any referee's toolbox. Coming up with a benefit or a hindrance on-the-fly can take some getting used to for the referee, but I find that by encouraging my players to make suggestions for what they might like to see, we can usually come up with something satisfying.