Rule Layout: side column summary

I think it's good to have some sort of "at a glance" rules. I don't know about putting them in a sidebar, though.

One common trick is to have reference cards included in the game, which players can keep beside them when playing, to summarize such things as turn order, scoring, or the cost and effect of certain actions or game elements.

I think the best thing, though, is just to employ good information design in the rules themselves. If each section of the rules is summarized by its first sentence, and you put those sentences in bold, it will both facilitate comprehension for a first-time reader, make it easy to look up the details about a specific rule, and make for easy skimming by someone needing to refresh their memory of the rules as a whole.

Alternately or additionally, providing a synopsis of the gameplay at the very beginning has similar value. One thing I find when explaining games to people is that sometimes the interplay between rule A and rule B is so tight that, whichever you start with, it's hard to understand it because you haven't heard the other yet. By giving the overview first, you make it easier for players to feel like "it's okay that Rule A doesn't make complete sense yet, because I know Rule B is coming up, and that'll make everything clear."

I first saw this layout in the late 80's, in some forgotten superhero role-playing game. At first I though this was a great innovation, but, as it turned out, the summary rarely proved useful. the main effect was to make the rulebook about 25% longer to fit in a mostly-empty column. We never trusted the summary enough to use it as-is. Rules simple enough to summarize effectively were usually too simple to forget.

I prefer the rules-summary card or cardstock sheet, personally. Far more effective, and easier to pass around during play. The summary column in the rulebook required keeping the rulebook in circulation, which was a drag. It's better to have a summary sheet that includes page references back to the rulebook.