Quote from VorpalCook makes a good point that the game master is at an unfair advantage over the players.
This normally wouldn't be a big deal if you're on traditional table top and are playing NPC's for players. Game masters would also have to make make accurate decisions according to the rules and be somewhat adversarial by default as they had to run the enemies as well. Switching between personalities, narrative and combat. It's a skillful juggling of your emotional energies.
But when you're competitively invested in a game, you could have both your hands on the bible and swear on your mommas grave and it's still gonna be suspicious.
Besides, you should consider how it'll effect the way the games feels. For example if the game master wins, what will they say? Can the other players gang up on you?
The best solution is usually to have another dungeon master, who can do it for you.
Yeah this is pretty much the bane of every game ever.
This only applies when the game master actually knows the game well and the players don't.
For a lot of games that are created and then played first time on Stick Page the game master hardly knows how to play optimally either, and for games that are fairly generic or simple the players know how to play if they just read. Even something as complex as Devour's Risky Business there are a lot of generic rts/war concepts that players would likely already have before playing.
I certainly wouldn't feel comfortable playing if players didn't understand any of the rules or I omitted things. And yeah, it's mostly for the player's sake I want trust build into the system.
Of course were I to actually go and build such a simple website for this purpose I would then be the one with access to the database and so Hewitt or you could use it but not me >.<.