This is the decisive battleground that sports a seven seas theme.
As a rule, Masters are forbidden from fighting outside of this battleground, however this rule is not strictly enforced. Those who break this rule are penalized, but not disqualified. If one so desires it’s possible to attack other Masters even in areas such as the arena and the school building.
However, there are several absolute rules that must be observed within the decisive battleground:
1: Servants only can attack Servants.
2: Masters can attack both Servants and Masters.
Within the game you do not have the freedom to choose to break these rules, but you do have the ability to directly attack other Masters using codecasts. It should be noted that even if a Master dies, their Servant does not immediately disappear, and if the dead Master’s Servant defeats the other Master’s Servant, the battle effectively ends in mutual destruction.
It might be contrary to what one would normally think, but what effectively determines victory is whose Servant defeated the enemy Servant.
The victor is the one who is alive and able to proceed to the next battle.
The loser is prevented from respawning by the firewall, and is fated to be completely blocked from re-entering the cyber world.
The world delimiting firewall is an impenetrable barrier, and only God-class Servants are be able to nullify it.
…Well, I guess some blonde hottie from Earth nullified it pretty easily. But that event was completely unrelated to Moon Cell, so it doesn’t count! The Funny Vamp who for the most part destroys Moon Cell’s rules through brute force.