[ORX] Interesting Question About Session & Campaign Length

A couple weeks ago, one of the kind folks who bought ORX wrote to me and asked a very observant question about the rules. Basically: when does a session end?

If that seems like a "duh" question, hold on, because there's a really good reason he asked. ORX is highly structured as a game. Similar to a boardgame or a CCG, everything you do happens in a precise order, with various conditions, bonuses, penalties and such being mechanically determined. It isn't at all like other RPGs in that sense. So the fact that a session doesn't have a set mechanical end-point to it is...well, a bit weird.

In a similar vein, he also asked when a campaign ends. Same thing there.

My answer to both was that "as in any RPG, they end when they end". Which I also mentioned is an answer that leaves me unsatisfied, precisely because ORX is so procedurally deterministic. That such is missing from the rules is a giant, gaping hole in the rules; and it was a hole in the rules I knew about, and had struggled with, when I published the game. Mainly because I never could come up with a decent way to handle it during the design process.

So, here's the challenge: based on the ruleset of ORX -- be it based on scoring, time, table-state, or otherwise as in CCGs like Magic, Vampire, Pokemon, and boardgames like Risk, Monopoly, and Chutes & Ladders -- using some sort of mechanical determinism, how would you do it?