Why I Like Binary Resolution Systems
Resolution system (noun): a system for determining the outcome of an action or a situation which uses randomized elements. (You probably already use this word, but better safe than sorry.)
Binary resolution system (noun): a resolution system that only gives two possible outcomes, generally some variety of success and failure respectively (Example: Cairn). Opposite to resolution systems with mixed successes, degrees of success, and other systems with more than two outcomes (Example: 24XX).
In most OSR games a roll (or Check, or Save, or Test, or however you want to call it) can have three outcomes:
- Total Success: the action succeeds with no additional cost to the one doing it / the situation has a positive outcome with no negative consequences.
- Success at Cost(s): the action succeeds, but there is a cost to the one doing it / the situation has an overall positive outcome, but the person involved loses something.
- Failure: the action fails with significant consequences / the situation has an overall negative outcome and results in some loss(es). N.B: In this framework, actions where the only consequences for failing are “try again” aren’t resolved with rolls, but succeed automatically.
There are more complex systems with more possible results (see Pugmire’s system) but most systems use at most three results with maybe a “crit success/fail” bolted on for extra dramatic value. That said, I like systems where rolls only have two possible outcomes - and this might seem counterintuitive, but it’s because they offer more variety. Let me explain.
In systems with three possible outcomes on each roll, the full spectrum of results is covered on every single roll made. A roll in 24XX, for instance, will always have the same “matrix” of possible outcomes - either total success, mixed success, or fail.
In binary resolution systems, the GM can instead choose which results to include before a roll is made. With two possible outcomes out of the full spectrum of three, there a three different matrices of outcomes to choose from, as opposed to the other systems’ one:
- Either a total success or a success at cost (ie. the action succeeds automatically, but you have the chance of losing something)
- Either a success at cost or a failure (ie. the action always costs something to attempt, but you have a chance of failing)
- Either a total success or a failure (you either succeed and lose nothing or fail and lose something).
There’s also another benefit, on the player’s side: bargaining ability. If, by using a binary system, the GM can easily play around with what results each outcome offers, and they communicate their decided outcomes to the players before the roll is made (see The ICI Doctrine), the player making the roll can “bargain” with the GM for a shift in the matrix of outcomes, by taking clever action in play. They may remove the cost from a success but add a greater risk to failure, or turn the chance of failure into a chance of success-at-cost if they put something greater at stake. The strategic aspect of weighing risk vs. reward is even bigger.
So! What can we do with this newly acquired knowledge? Make games with binary resolution, for one. But also, use them wisely. Have fun!