Deciding on what system to use in play defines what kind of experience you’ll have during a session. When it comes to choosing a game, there are three dials or settings that I always consider before deciding on a particular system. What are the resolution mechanics? How lethal is the game going to be? How are characters created? Those three questions help me decide if the system is what I’m looking for.
First, there are the resolution mechanics. Some games are binary: you pass or you fail. Personally, I don’t like those. While the GM can take inspiration from Dungeon World and use GM Moves to narrate why something fails, it’s still a yes or no kind of thing; allowing for “yes, but” and “no, and” results changes the system. Which subtly turns it into a different style of mechanic: you pass, you pass or fail with consequences or you fail. This is something that games like Dungeon World, Forthright Open Roleplay and Freeform Universal RPG already does. So it becomes a question of, “How much tweaking of the resolution mechanic does this system require vs. is there a system that already does what I want?” I almost always default to the latter and choose something non-binary for resolution.
Second, how lethal do I want the session to be? I’ve been gaming for almost 35 years. Sometimes, I want to recapture the feel of classic D&D where a character can simply die because that’s the way the dice happened to roll. For example, Vasilis made it all of four paragraphs into the session before a random trap just killed him, and I was alright with that. However, I went in knowing that’s the experience I was going to have. A system that allows for Stress and Consequences, such as Fate, will have a different expectation. In Visemar’s case, he eventually had all his Stress boxes checked but was still safe from dying. Whereas in Forthright Open Roleplay, death is something that needs to be implicitly implied by the Guide so the player understands that death is a viable option of failure. I set this dial in tandem with the last question, “How are characters created?”
How much time I invest in a character during creation guides my choice of system for lethality and system. I don’t mind when a character dies in Swords & Wizardry Continual Light because I can make a new one in less than five minutes. I don’t mind putting a character in stressful situations in Fate because, as demonstrated by Tiny Fate, character creation is just a name with a few Aspects. As much as I like Runequest, I probably won’t choose Mythras / Runequest 6 because I don’t want to invest the time to roll up a character, distribute up to 250 skill points then have the character randomly die in one sword thrust. Duration over creation crosses Runequest off my list of systems. Naturally, I can always tweak the lethality dial, but that goes right back to question one: Is there a system that already does what I want?
Once I’ve set the duration over creation dial, I know how lethal I want the experience to be. Part of that lethality implies resolution mechanic: D&D style combat and task resolution or something like Tiny Fate or Dungeon World resolution. After those three options are finalized, I know what type of system I’m looking for. I can use a game from my library pretty much as is or create my own experience by tuning a game system to better suit my needs. When it comes to choosing what you want to play, choose what type of experience you want to have. The system will start to fall into place as something already available or something you can create.