Now for a post that only about 1 reader I know about might find intersting. A post about something that I have been pondering for quite a while. How the rules in an RPG influence that game being played. I mean most people wouldn't use the White Wolf 10-sider system to potrait a realistic war simulation, nor would they use the ultra realisitic Rolemaster system for a cinematic Hong Kong Kung fu movie game. Those are extreme case but I have come to belive that the influence of the rules system on the game is much more profound.
Take for exemple D20 (the dungeon and Dragon system) and the Star Wars D20 system (both are basically the same system at one big execption how they handle character vitalllity i.e how hard they are to kill), In the usual D20 system it is very hard to kill an high level character, they almost always have 100 of hit points, saves that allows them to survive the average and not so average vilain killer attack and an armor class the rivalise armored battleship of modern time. On the other hand the Star Wars D20 system makes high level character very easy to kill, at most they can take one or two blaster hits and go down (a character can only survive damage up to his constitution) and while their save can allow them to dodge a nuclear explosion at close range the half damage rules means they still die.
What does that means when play times comes, well the action will be very different, in standard D20 you will see people basicly standing in front of each other and hiting each other with kitchen ustensil until one or the other run outs of hit points. While in the Star Wars game people (even jedi to a lesser extend) will dodge and run for cover trying for lucky shot, incredible movies like move and generally tries to be more negotiating.
I often hear DM that the system in which they play the game is not important and I always wondering how this can be true, so much rest on the system even if the DM is fudging for the players it remains that the system are like the laws of physics and they kinda define how your character will be influence and should react to event around him. The D20 hit points system for example makes it easy for people to fight long battle where a minutes advantages in one round will not matter much as it will have a very small impact on survivability. Other system like Alternity and White Wolf with characters that can take very few hits bring for short intense combat where a small temporary advantages can shift the course of the battle. That probably means in short that you should always consider the system your going to use with your game.