Crunch Criteria

I'm gunna be a little self-indulgent and quote myself.

Every piece of crunch you add has a cost. A cost in how much brainpower it takes to learn, to teach, to remember, to use. The essential tradeoff is to make sure that crunch is able to add something really valuable to the game in spite of that cost. I try to only add crunch in the parts of the experience that I think have the most potential for interesting decision-making.

This isn't just talk. I actually have a set of standards I apply when it comes to "justifying crunch" in a system. It's a hierarchy of three levels.

The Intuition Standard

The best mechanics are usually intuitive. After reading it you might think to yourself "well gee, I didn't even need that to be written down!" Of course, there is still a value in codifying common sense rules, but the nice thing about intuitive rules is that you'll probably never need to read them twice. I know a lot of old-schoolers are insistent on the importance of never ever ever pulling out a rulebook during play. I think it's an overblown issue but in general I agree that it's best to maintain a smooth flow of play. Interruptions are annoying. But the important takeaway, which isn't said frequently enough, is that if you want to achieve that "no rulebooks at the table" playstyle, then the best answer is to play an intuitive ruleset. Developing the skill of making rulings on the fly is really helpful, but I would prefer to pick a system that doesn't force me to do that very often.

For example, in D&D 5E being in dim light imposes disadvantage on sight-based checks while full darkness makes them impossible. I think that makes perfect sense. If I had never read that rule and I instead had to make an ad hoc ruling at the table, it almost certainly would have been identical.

The Memory Standard

The second-best mechanics are memorizable. Making all your mechanics perfectly intuitive is an ideal, and one that you'll probably fall short of if you're designing a really fleshed-out system. That's okay. It's too high a standard to hold yourself to 100% of the time. So when you play a game and your intuition fails you, you fall back on simply memorizing the rule. The mechanic might be a bit arbitrary but sometimes it's worth the mental load of just committing to a system and memorizing all its little quirks.

For example, in D&D 5E I just had to memorize the rule that the standard d20 check is of the "meet or beat" variety, where you have to get greater than or equal to the DC in order to succeed. Most of 5E's crunch is at this level. Falling damage is 1d6 per 10 feet fallen, characters can attune to a maximum of 3 magic items, and when you take a short rest you can spend your hit dice to heal (adding your Constitution modifier to each die you roll). See? Not too hard.

The Reference Standard

The third-best mechanics are easy to look up.  When your intuition fails you and your memory fails you, you fall back on simply looking up the rule. Sometimes you're just really married to a particular mechanic, likely a whole subsystem, that is neither intuitive nor easy to memorize. As a designer, it's risky to include crunch like this. But as long as you make it easy for the player or GM to reference during play then you can get away with it. Sometimes it's genuinely worth it! There are many great games that contain tons of crunch which falls into this category. In the old classic TSR game Marvel Super Heroes (AKA FASERIP), all play revolves around this ridiculous matrix that looks like the periodic table of elements, which has a gazillion variables involved that are used to resolve basically anything that could ever come up in play. Intuitive? No. Memorizable? Hell no. But that's why the matrix is reprinted in full on the back cover of the rulebook. For a resource like that, which you'll be using every couple of minutes throughout every session, it's definitely worth such prime real estate. So what's funny about this criterion is that it's largely a matter of layout optimization rather than actual mechanical design. Character sheets are your best friend here, so think hard about the best information to include on them.

For example, in D&D 5E I can't imagine any spellcaster will easily memorize all their spell slots. You have many levels of slots, each with a different amount per level, plus you have to track which ones are spent and which ones are still available, etc. But it's not hard to write this stuff down so it's no big deal.

"Bad Crunch"

The worst mechanics are the ones that fail all three of these criteria. That's what you really want to avoid. Attacks of Opportunity in 3E D&D are not remembered fondly by most of the RPG world. Which actions provoked an AoO and which ones didn't was often arbitrary and nonsensical so you couldn't just intuit it, there were dozens of them so you couldn't memorize the list, and looking up the chart in the rulebook every single turn was a pain in the ass.

I think that the worst offender in all of 5E D&D are the exhaustion rules. It comes in six levels, each of which has its own specific penalty, and which are really hard to memorize. Even if you do remember them, they’re juuuust fiddly enough that you’ll always look up the exact rule every single time it ever comes up in play, just in case. It's not on the character sheet and it's hidden in this one really inconvenient part of the appendices. It sucks.

This isn't just talk. Apply this in your design.

When I was working on Brave, I found success in all three standards.

I kept refining my dungeoncrawling procedure until it perfectly matched the intuition of pretty much everyone I ran the game for. One of my stress-testers was finding a brand new player, someone who's never played an RPG before, and then running them through a dungeon where the procedure was exclusively GM-facing. They didn't know the rules for dungeoncrawling, so they just declared actions based on common sense. If what they wanted to do was clashing with my procedure's constraints, I had to refine it. When I got to the point where all their actions could be perfectly simulated within my procedure, I knew it had finally met that Intuition Standard.

Most other bits of crunch I added or tweaked, I made sure to keep simple. 1 fatigue fills 1 item slot, fragile weapons lose 1 quality every time they hit something, and characters on horseback have +2 AC and +2 attack against enemies on the ground. I was unsure about the famous Usage Die mechanic at first, but I introduced it to two groups of players and in both cases, pretty much everyone memorized how it works within a session or two. So it made the cut for the Memory Standard.

One of my favorite bits of crunch in Brave, and one which sets it apart from pretty much every other major Knave hack, is the Death and Injury table. It's an old houserule that was popular in the early OSR blogosphere. Instead of dying immediately at 0 HP, you roll on a table to see if you die, get dismembered, get stunned, get knocked over, etc. It's chaotic and grindhouse-y and fun. My version was adapted from Trollsmyth's (James Brian Murphy), itself adapted from Robert Fisher's. The problem is that this is a 2d6 table of 10 unique, non-linear, non-uniformly-scaling results that you may find yourself rolling on every single combat encounter. So I decided it was worth the real estate to copy the table in its entirety onto the character sheet itself. I also like the message it sends: you get your character sheet and right in your face is a table of horrible ways your character will get mangled. So even though I said before that mechanics at the bottom of this hierarchy are the "third-best," I actually think this is one of the best bits of crunch in my game. It adds more worth than it costs.

-Dwiz