He who brings the weed gets the green hit (There are exceptions, like if its someone elses house, they get the first hit)

No bogarting

No talking whilst toking (This has been the end to many a buzz in social circles)

No bitching about the weed, if you got a problem, you can be sober for all I care

Roller's Right's (But this usually pertains to packing bowls in pipes/bongs etc.)

Bring your own lighters (This one people are usually mellow with)

Tell moochers if they don't pitch, they can be the sober ones, nobody mooches off my bud.