There is a great deal of thoughtful consideration here and some very interesting ideas. This is what the Downs is all about--people reflecting on things and sharing their ideas intelligently and graciously!
I would have to say that I give rep as
Mark12_30 does, for individual RPG posts, whether in games or in Inns. In fact, I have consciously made an effort to rep gaming posts as I recognise that many good gamers do not regularly post in other forums. And I have wanted to encourage gamers by showing that their good work and effort is appreciated.
To give a specific example, there were posts in a game I recently finished, Land of Darkness, which showed excellent writing and good character development (ie, an elaboration of something hinted at in the original bio, or a new aspect brought out by the interaction), and which extended the plot and reached out to incorporate other characters. I don't think one needs to wait to the end of a game to see imagination and interactive writing, although clearly such important qualities as reliability and dedication are probably best seen over the duration of a game. And while it is true that some aspects of a game might take several posts to develope, it is possible to see that development set in motion in posts.
In fact, I would argue that in interactive gaming, it is crucial to see that development in individual posts. For gaming to be truly interactive, the posts ought to be the main thing wherein the other gamers can take their cue. (I would argue that this is crucial for readers as well, in good games.) If too extensive planning is done behind the scenes--in my experience--the posts become plodding and perfunctory and gamers pick up a sense of "well, it isn't my turn" instead of responding imaginatively and creatively to the writing on the "page" in front of them.
[Edit added here] I'm not surprised that good rep is given out more often than negative. On the one hand, people respond best to positive measures than negative. And on this forum, the standard of decorum and civility is very clear and well moderated. [end edit] I've given negative rep for a post (really a series of posts) which attacked another Downer personally, in a discussion which got very heated on one side in particular. And I've done this when a PM did not seem to change the gamer's approach to handling difference of opinion. (This was on a thread about religion--of all places!) I suppose the internet lingo for this is "flame". We don't all have to agree all the time on everything and to me one of the great beauties of discussion forums is the way they incorporate differences and consider other points of view. I've learnt alot listening to people I haven't understood or agreed with. (Just ask
davem 
)
There was one other time when I gave a negative rep to a post which concerned a gaming issue and one of the qualities or standards which Barrow Downs games represent, when I felt that repeated posts showed the gamer was not understanding the issue and I thought a wake-up call might be valuable. In retrospect, I probably should have used a PM. But I made up for it by repping excellent work from the gamer when I saw it.
To tell you the truth,
Imladris, I don't know what a rep of mine is worth. And the value of a rep changes, as a Downer accrues posts and points.
[edit]And I will take this opportunity to thank everyone who has repped me. I am astounded to find myself with five 'boxes' and third after those titans,
Fordim Hedgethistle and davem. I guess the words I use aren't too big after all.
[end edit]