A sith law making it so that there can never be more than two active sith at one time, one master, and one pupil. The rule was set in place by Darth Bane after he killed all the other sith.(Darth bane also started the tradition of prefixing sith names with "darth")
Darth Sideous only ever had one deciple at a time, first Darth Maul, then Darth Tyranus, then Darth Vader. Although he surounded himself with other Dark Jedi, there were only ever two Sith at one time, in accordance with the Rule Of Two.
by SlackerApathy August 19, 2005
Get the the rule of two mug.
While a one night stand makes her feel used, a second hookup validates her worth. Then bail.
Remember that slut from the bar? Yeah, I used the rule of two on her.
by Lionel Matson December 27, 2011
Get the Rule of Two mug.
As stated in Alice's Adventures in Wonderland: "All persons more than a mile high, to leave the court."
Quote:

At this moment the King, who had been for some time busily writing in his note-book, cackled out 'Silence!' and read out from his book, 'Rule Forty-two. ALL PERSONS MORE THAN A MILE HIGH TO LEAVE THE COURT.'

Everybody looked at Alice.

'I'M not a mile high,' said Alice.

'You are,' said the King.

'Nearly two miles high,' added the Queen.

'Well, I shan't go, at any rate,' said Alice: 'besides, that's not a regular rule: you invented it just now.'

'It's the oldest rule in the book,' said the King.

'Then it ought to be Number One,' said Alice.
by arkizzle October 11, 2009
Get the Rule Forty-two mug.
Fundamental rule of dating females, no fat chicks
1: two rules of dating my friend, rule number one is there are no rules
2: what about rule number two?
1: no fat chicks

Don't date Hayley, she's a rule number two
by tdpass6000 January 4, 2017
Get the Rule Number Two mug.
All persons over a mile high should not be in court. It is the oldest rule in the book.
At this moment the King, who had been for some time busily writing in his note-book, cackled out 'Silence!' and read out from his book, 'Rule Forty-two. ALL PERSONS MORE THAN A MILE HIGH TO LEAVE THE COURT.'

Everybody looked at Alice.

'I'M not a mile high,' said Alice.

'You are,' said the King.

'Nearly two miles high,' added the Queen.

'Well, I shan't go, at any rate,' said Alice: 'besides, that's not a regular rule: you invented it just now.'

'It's the oldest rule in the book,' said the King.
by OrangeAipom January 15, 2010
Get the Rule Forty-two mug.