My general policy with new rules systems has always been to try them 100% Rules As Written - at least for the first session or two. If there's something that proves problematic in play, then I'll make a note of it and bring a solution to the next running (either from a different iteration of D&D, from the Web, or from my own rapidly-decaying positronic brain). When I ran Drunk D&D, I made sure to stick to RAW as closely as humanly possible, and I ultimately succeeded without any of the PCs dying.
|I doubt that anyone under the age of 50 (besides me) will laugh at this.|
(You might notice that my above description specifically excludes certain iterations of the game; if you've read my past posts, you'll know which ones they are without my having to name them here.)
Referring to the rulebook in all but the most fringe cases also gives an important impression to new players: this is a game. Games have rules, and it's sticking to them that gives a game its challenge. When I was a kid, I made liberal use of cheat codes and external devices in my video games, but as I grew up I understood that I never really beat those games - I had cheated my way through the game, and by doing so I cheated myself of some rich experiences. (I have no regrets about a few of those, though; to steal a line from El Santo, Super Mario Land sucks so hard it has an event horizon.)
One particularly glaring issue came up for me recently in AD&D 2nd Edition, thanks to some experiences in both the game world and the "real" world... but that's a topic for another post. Probably the next one (if my own laziness doesn't catch up with me), so stay tuned!