The premise: The PC's are together in a virtual environment (similar to the moon cell). They live in a large city, competing in the grail war and passing the days in any way they see fit. In short, players can be any character they wish (with approval of course). They interact, fight and so on as they see fit, with the addition of plot hook events dropped by me as the GM.
Game flow: The main premise allows for characters to do anything. However, this has two restrictions. Just like the grail wars, fighting is confined to the night time, to this end there is a time cycle game mechanic. Secondly, while every NPC and enemy servant can be killed for experience points, anyone attacking disqualified servants, NPCs or other non combat parties will suffer an attack by the system. It's not a penalty strictly speaking but it is not advisable.
Time cycle: Every three real-world days, the cycle moves forward. Day to night, night to day and so on, repeating. Barring special circumstances, this cycle is impossible to change.
Day: This is the social time of the game, a break from combat in the streets outside (although characters can stay indoors to avoid all danger from programs during the night and effectively use this as a social time as well).
Night: Programs are unleashed to allow characters to train and the grail war is active, allowing servants to fight.
Penalties: Aside from the in-game penalties that occur in Extra for breaking the rules, there are a few penalties that are for players should they become disruptive.
1) Suspension of experience, items and or powers.
2) Restriction of character actions, or removal of the right to play a character.
3) Expulsion from the game.
These are the penalties I have in place. In short, three strikes and you're out.
All combat and actions are resolved with the roll of a twenty sided die.
2-9: Failure or miss
10-14: Sub-par success, glancing blow (the opposing side takes no damage but contact is made)
15-19: Hit, success
20: Perfect success/strike
A fumble is followed by another roll, if it comes up 1 again then it is a critical failure and a rebound occurs, damaging the character in some fashion.
A perfect success is followed by another roll. If 15 or more is rolled, then it is a critical success. If 20 is rolled then another roll occurs, 15 or higher is considered to be an exceptional success, exceeding the user's ability. In combat, the opposing side is defeated instantly.
Character creation (maximum three active characters per player)
Name: (real name and aliases)
Class: (if servant. Saber, Lancer, Archer, Rider, Caster, Berserker, Assassin)
Race: (human, dragon, vampire etcetera)
Skills: (maximum five)
Noble phantasm: (maximum ten)
Characters start with E rank or zero in their stats. The stronger the phantasm or skill, the higher the level you will have to be to unlock it.
1) role play as the dice fall, if you take a critical don't shrug it off it your description of it should reflect the damage taken.
2) Be respectful of others, GM and players alike, we are all here to have fun.
3) Don't harass players or otherwise bring outside baggage to the game.
4) Don't complain about the dice, sometimes you'll get your butt kicked, it's part of the game.
5) PCs don't die when killed, they're just revived with a small exp loss. No matter what your character can do, it cannot over ride this system directive.