At this point, I've written the rules for over twenty-five published games that I've designed. I've also rewritten, with Mary's help, the rules for about a half-dozen other games by other designers. So, at this point, writing rules is second nature to me; it's easy-peasy.
It didn't always used to be that way, of course, but like I said, I've done this something like thirty-plus times, and after the first dozen games or so, I simply had to get better at it. The other thing is that over time I became much more confident in writing the rules my own way, utilizing my own voice. When I first started out, that wasn't the case. I very much wanted rules that read and felt like everybody else's. You can see this in the rules for my first published game, 2012's Blood on the Alma, which was written in a fairly dry, colorless style. This extended to the organization of the rules as well, with cases and sub-cases and sub-sub-cases: after all, this is a very serious, very historical conflict simulation, so one mustn't forget rule six point two point three point one.
Though Alma was my first published game, it wasn't my first game to be accepted by a publisher; that was a Euro-style horse-breeding game which unfortunately never did see the light of day. Those rules weren't written in a case format, but they still were designed very deliberately to look and read like everybody else's for Euro-style games, both in structure and in content. Despite that, I simply couldn't resist slipping in a joke:
When you replace your breeding mare, it is sent to a glue factory. Just kidding, but it is removed from the game.
That was one of the first things that was struck from the rules. Partially, this was because the joke was a little dark for an ostensibly family-friendly game (though, let's be honest, in any game about animal husbandry, the table talk can get pretty blue with the right group), and partially, this was because the reference was seen as ambiguous: we didn't reference a glue factory anywhere else in the rules, and some players might be confused.
This only reinforced for me the idea that humor and personal style, or anything idiosyncratic or eccentric, had zero place in the rulebook. Keeping myself entertained and engaged, let alone the reader, wasn't an option. Which made the whole exercise a kind of pleasant drudgery, like sorting cubes or punching out counters - something I needed to be in the right mood for.
But then I bought my first Richard Berg game. It was Glory III, and I had picked it up, unpunched, for two bucks at a yard sale. Technically, the two bucks were exchanged for both Glory III and The Blue and the Gray, the boxes of which had been rubber-banded together, but upon opening the latter I discovered that all the cards and the mapboard were missing, leaving me with a rulebook and an empty box. But Glory III made a big impression on me for a couple of reasons. One of these is that I didn't really like the game all that much: playing its Antietam scenario took roughly the same amount of time as the battle took in real life, and I have a strong dislike of ten-sided dice, facing rules, and command-spans - except, oddly, in Great Battles of Alexander (which of course Mr. Berg co-designed with Mark Herman), where all three are not only not a problem, but a source of delight.
But the other reason the game made an impression on me, and the one actually kosher to our discussion today, has to do with the way Mr. Berg wrote his rules. There was a sense of humor about the proceedings that I hadn't really encountered before, from snarky little asides to goofy scenario titles (IIRC, the "what if Grant was in charge?" scenario was called, Great Googly Moogly, Get Me Out of Here!). The whole package just had a lot more personality than I was used to seeing, and more-or-less let me know that it was okay to do that.
And so slowly, as more and more of my wargames were published, I became more comfortable slipping little bits of irreverent humor into the mix. This started with the historical background material rather than the rules proper. You can see this, for example, in the run-down of eleventh-century English dynastic politics that accompanies House of Normandy, in which the number of important women named Matilda becomes something of a running gag.
Eventually this kind of poured over into the rules proper, usually in some small way. For example, in Agricola, Master of Britain, failure to remove Calgacus from the map results in an automatic defeat. After stating this, I admonish the player: "So, get that guy." In Supply Lines of the American Revolution, I deal with an edge case by saying that rule such-and-such "is an exception, rules lawyers". In our forthcoming Shot & Shell series, I introduce Zones of Control, one of the standardest of standard wargaming mechanisms, with "Stop me if you've heard this one before."
This tendency probably reached its apex - and very well may have gone too far - in High Speed Hover Tank, a science-fiction game I did for another publisher that sold maybe four copies. (We might republish some day after the rights revert back to us, but we'd probably sell only five copies.) That was a very irreverent game, and so the rules were infused with an irreverent and flippant tone: weapon ranges were explained with "because lasers or something", and there was a rule against being boring and dumb: "Don't be boring and dumb. It's against the rules".
I haven't gone quite that far with my historical designs, but I do try to use humor where appropriate to liven up the proceedings and to make specific rules more memorable. I also generally try to write my rules in a less technical and more conversational style. I tend to approach it as, if I was teaching the game to somebody in-person, how would I phrase this or explain that? The other way I look at it is, how can I make reading the rules less of a chore?
I write to give pleasure, and I read for the same reason. Even when there's no humor involved, there's something distinctly wonderful about a well-crafted sentence, about the way certain words sound together, about the way one sentence builds upon another upon another, about the slight natural pauses of a comma and the professorial precision of a semi-colon. Whether I'm writing a blog article like this one, or a trashy novel about lesbian aliens fighting dinosaurs (which is a real thing that I've done*), I strive to provide a smooth, stylish reading experience. I put a tremendous amount of effort into appearing effortless.
And it's only natural for me that I try to do the same thing with my rulesets. That my "voice" be personable and recognizable, and that, in some small way, reading my rules gives the player some degree of pleasure. Some days I'm more successful than others: there's only so many different ways to express the idea of moving across contiguous hexes, spending Movement Points for each hex entered, and it's difficult to spice up rules for retreats and advances.
But in the end, these are games, and however serious they may be, they ought to be fun, so it makes sense to try to extend that to reading (and writing) the rules.
[* - Mary is my biggest fan.]