Mechanical difficulties

I haven't run a lot of games. (In fact, I've run precisely two: Memento and the ongoing Once Upon a Time in the West, plus one almost completely rules-free LARP session.) In the case of Memento, going into that game, I had a large amount of familiarity with the LARP mechanics for Changeling (i.e. what sorts of things their powers did, though there were occasional points of massive discrepancy between the two sets of rules), and a similarly large amount of familiarity with basic World of Dar...