Several of the games I played didn't have written rules. I don't know if this is a "we didn't have time because hecticness" thing, or if there's an idea that needing written rules means you're game's too complicated, or what, but knowing what sorts of things are likely to happen in game ahead of time (whether there's a combat system, whether there's a non-default game structure, etc.) is helpful for getting into character mode, and I definitely think it's useful to get everyone on the same page.
Similarly, games at Intercon often don't really have a wrapup. There are some good reasons for this, with the tight schedule, but I personally find it makes my plots feel like they matter less if there's no general knowledge of what was going on with them. Also, some games are sufficiently weird and mysterious during game that not having at least some overview of what was really going on makes looking back on game confusing, and casual chatting after game is less effective for these games since everyone has different interpretations. Since players may not be able to stick around after game ends in an Intercon setting, I think written wrapup documents being more common would be cool, though that's additional work for GMs, especially for first-run games.
Finally, something about "valence" (can you tell I've been playing WTF?). I understand that some LARPs avoid strong character goals because they're trying to avoid "play to win"-style behavior, and I'm totally down with focusing on roleplay and playing characters that have impossible goals or where the player goals and the character goals don't line up. But, I still want the choices I make in game to matter, whether for the good or ill of my character. Related to what I said before about wrapup, if my actions have neither in-game effects nor post-game effects other players know about, that makes it harder to get immersed in the story. I think this is especially an issue at Intercon LARPs, because they're relatively short and transient and they compete with other LARPs the same weekend for anticipation/prep time. And for me, this is especially an issue for "tales"-style scene games where you don't have a consistent character from scene to scene and your decisions in a scene don't ripple forward in a way that solidly impacts following scenes. Since I don't have a lot of time to get invested in a character and the choices I make don't seem to affect anything, it's low valence and makes it feel less like a LARP and more like a non-interactive story.
That's enough about Intercon for now. Join me next arbitrary length of time, where I either poke a stick at the mysterious mass of LARP categorization or talk about open vs closed worlds in different types of role-playing games.