Creating a single page TTRPG seems like it should be a walk in the park. You don't need to fill 300 pages of setting, bulky mechanics, and big old tables. But just like how short stories have their own challenges compared to novels, so do micro roleplaying games.
When designing a one-pager, the creator must distill as much information as possible so that players can run the game, but keep things lean enough for the physical limitations they're playing with. This is actually a tough tightrope to walk if you want to create an effective game.
Today I wanted to zoom in on one crucial part of the one-page TTRPG design process: the core mechanic.
Everything hangs on the core mechanic
Many longer games have a core mechanic that determines the rule-feel, which is like mouth-feel but for nerds. The core mechanic is generally a single resolution that interacts with secondary and tertiary mechanics. This mechanic determines how players interact with the world, resolving conflict, and the consequences they face.
With a longer game (maximalist? big?) a core mechanic is the cornerstone surrounded by other mechanics. In The One Ring the core mechanic requires rolling a d12 containing a Sauron eye and a Gandalf rune as well as other numbers, along with several d6s with a specific rune as the 6. The mechanic is information rich, interacting with meta-currencies like shadow points, load, armour, and more. It's a beautiful game, but the sheer web of mechanical complexity (though simple to ultimately comprehend) makes it work only in the longform.
In a one-pager you're highly limited in how much explanation you can offer, so something like The One Ring likely couldn't exist in a meaningful way. Might be worth a shot, though.
No, your core mechanic needs to be a statement that powers the game without getting in the way of itself.
Matching the core mechanic to your desired experience
With a small wordcount, the core mechanic is going to largely determine your game's feel. It may seem obvious, but you need to start by knowing what your game is actually about and find the right mechanic to connect it. I don't mean just knowing your game is about a group of netrunners trying to steal money from corpos. It's understanding what you want the players to experience in the game. Is it about rising tension? Cinematic combat? Social bartering? With a game like CBR+PNK all the rules ladder up to letting the group play out one last job. In my own game Nightblade I wanted to distill the cinematic combat of 13th Age and 4th edition into a tiny game.
Your core mechanic needs to create your game's signature moment immediately. If it's one about escalating tension then an exploding mechanic where more dice are rolled when a 6 comes up can simulate either an action going very well or very badly.
Five mechanics and what they can do for your game
D6 triage: This is simply where each die result has a different tier of severity. This is ultra-simple, quick to teach and can help hit specific narrative beats. Lasers and Feelings does this well, with quick play and clear outcomes.
Roll + stat vs TN: Maybe the most common trad mechanic. Roll a die, add a stat or skill and compare to a target number. Much of the time this is pass/fail binary, sometimes with critical successes and failures for rolling naturally high or low. Good for a game where you want to get more granular with difficulty.
Dice pool/highest die: For example, rolling a bunch of d6s and looking for the highest, or counting a number of successes. I used this in Dark Graal (alright, not quite one page, but lite enough) to have some cinematic variance without the need for granularity. I also allowed 1s to cancel 6s to keep tension high.
Push mechanic: Risk/reward that ratchets up tension while empowering the players to push their luck for the result they want. This is great when you want clutch moments to feel meaningful. Spending tokens can improve the players' chances of success.
Card draw: Cards are information rich (colours, suits, numbers, card types) that allow for low maths outcomes and granularity without the bookkeeping. This works especially well for narrative games, since it's easy to map suits to narrative outcomes.
Implementing your mechanic
Determine your outcomes based on the chosen mechanic. Ensure these feed into your gameplay loop.
Offer an example of use in play. Keep it zippy.
Set your default target numbers or standard modifiers. Don't overload modifier types - choose a maximum of two (for instance, D&D's advantage/disadvantage)
Decide clear consequences (narrative/ impact on resources/ complication)
Specify any meta-currencies and how they impact the core mechanic. Keep this simple but thematic
Add a one-sentence GM tip for running the mechanic smoothly
And finally
You will probably find yourself swapping out mechanics until you find your desired playstyle. It's important to keep iterating until you hit the moments you outlined from the beginning.
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