Get your mind out of the gutter. What I’m talking about here is the number of sides on a die. Specifically, how the number of sides on a die can affect task resolution and game play. I recently wrote a post on Traveller, and soon after I posted it I of course went off to read and reread through everything I could get my hands on for character generation. Cause that’s what I do. I’m an addict.
I found myself wondering at the core dice mechanic use of 2d6, or as it’s notated in Traveller, 2D. To be successful, you must roll 8 or better on average difficulty (for Mongoose’s second edition; it may be slightly different in earlier versions or editions), adding up the 2d6 roll and then adding your character’s Dice Modifier (or DM). That step, specifically the adding of the dice modifier, is what sent me down the rabbit hole of the mechanics of the thing. If the roll is only 2d6, then a +1 has a much greater influence on the success or failure of the task than a +1 would be in a game where it is added to a d20 roll. Dungeons and Dragons, for example, uses the d20 roll where players again add dice modifiers which are called attribute modifiers or skill levels in that game. With the d20 being a stand in for a percentage chance (but much better than a straight percentage roll due to it’s open-endedness), a bonus of +1 is really only a 5% increase. With 2d6, however, that same +1 is a little over 8%. Small difference, really. What if you scale it up, though? Most characters at start in both games can usually pull off at least a +3 for things they are good at, maybe a +4 if they are very specialized. The higher the bonuses, the greater the difference in success rates.
For me, that’s the core of the problem I have when deciding which system I prefer to use. I like a wider range of dice results, up to a point. I’m not a fan of straight percentile systems, as you can read in an earlier post (see https://dicemechanic.org/2017/04/05/the-silverback-paradox/ for details), but then again anything with a very small range such as just 1-10 or 1-12 isn’t satisfying because I don’t feel like it gives the Gamemaster enough wiggle room to make different tasks really feel different. 2d6 also feels restrictive, even though 1d20 is less dice. It’s a touchy-feely thing that I may not have been able to describe properly in this post. Again, get your mind out of the gutter.