There Can Be Only One
Sanctuary on Holy Ground
No Immortal may take another's head on consecrated ground, regardless of the antiquity or origin of the consecration.
There are only two possible recorded instances of an immortal breaking this rule: Pompeii, A.D. 79 - immediately before the eruption of Mt. Vesuvius, and the Watcher Sanctuary in 2004, when Jacob Kell slaughtered the Immortals gathered there. Immortals may experience / witness warning signs when they are about to break the rule - such as in the fight between Connor MacLeod and the warrior Kane in 1994.
One on One
No two or more immortals may attack another simultaneously, or interfere with an immortal duel in any way. While considered a major rule, this rule has no real consequence other than preventing other immortals from sharing a Quickening or gaining an unfair advantage. Thus, it is the rule most often bent or broken by evil immortals - for examples see Xavier St. Cloud, Jacob Kell, and Jacob Kell's Gang.
Beside the three major rules, immortals have the following commonly understood and accepted rules and customs:
- They must keep their challenges and affairs secret from the mortal world.
- Immortals normally do not fight or discuss their business in public. The only exception is within relationships, as immortals sometimes share the entire truth of their existence with their significant other.
- Immortals who "die" in public are expected to leave the area, in order to avoid contact with those who knew them.
- New / young immortals are assumed a brief "grace period" in which they receive training and protection from an elder immortal.
In addition, many immortals bind their own codes of ethics within the Rules, often issuing their challenges against those immortals who have offended their personal morals in some way or fashion.