In Nomine/YMMV


 * Adaptation Displacement: Chances are, if you've ever heard of the original game, it was through the Steve Jackson version.
 * Alternate Character Interpretation: The game is loaded with them, and two or three are suggested for every Archangel/Demon Prince supplement. Dominic may be an ineffectual nanny, an uncompromising tyrant, an outright Balseraph in disguise, or the smartest, most clear-eyed person in Heaven. Yves may be a secret mastermind, a doddering old man, or God in a George Burns costume. Lucifer, Valefor, Alaemon, and/or Kobal may be working for God. Valefor might actually be Lucifer. Or Valefor (a Demon Prince) and Janus (an Archangel) might be the same person. And in the French game, you can remove the latter "might". He is also Hermes.
 * The GM's Guide has options for giving the entire game an Alternate Character Interpretation. 'Backwards' has the angels all being Knight Templar fanatics and the demons being heroic rebels. 'Dark Low Contrast' is basically doing it Garth Ennis style, where both sides just plain suck. 'Bright Low Contrast' is the sitcom version, with Heaven being well-meaning bumblers and Hell being Punch Clock Villains with no actual malice.
 * Anvilicious: Television (and by inference, movies, network news, and reality TV) were invented by Hell. Oddly, the Internet and "new media" in general are not; those are creations of humanity and the angels and demons are currently racing each other to try and take it over.
 * As revealed by 'Superiors 4', while Heaven may have created the idea of wages, Hell created the concept of taxation.