As a member of the Vandals, you're expected to respect that ultimatley the point of Mabinogi is to have fun. You should never act in any way that interferes with others enjoyment of the game. Try to be conscious of others, and just don't be a dick =). It's the core principal and value of the Vandals.
Members are also encouraged to follow the PvP "Code of Chivalry". Which consists of a few basic tenets:
(This is not a requirement. The only PvP requirement of the Vandals is the same as our ONLY real requirement: Don't be a dick.)
1.) Thou Shalt not Random-
While this is one of the lesser and more flexible tenets, it still stands that PvP should have a reason. If someone doesn't want to PvP; don't force them to.
2.) Thou Shalt not Camp-
You should never "camp" another player. "Camping" is when a player or group of players continually attack another player and don't allow them to get up, and often type obscenities. This essentially puts the player being camped in Limbo. They are unable to turn off PvP or retaliate; and are forced to lay there unconscious or stand up only to die again. It's the most vile of PvP taboos in Mabinogi. Continually killing an aggressor in an attempt to let another player escape pvp is accepted by the code, however.
3.) Thou Shalt Assist Those Being Camped-
If you see another player being camped, and are unable to assist, inform them that they can type "/logout" to exit the game and change channels. If you are able to help someone being camped, even in the face of a loosing battle, you must come to the player's aid. Should you be defeated, call for back up, or resort to informing them of /logout and live to fight another day.
4.) Thou Shalt Not Flame-
Flaming is useless and excessive name calling, abusive speech etc. in PvP. Again, don't be a dick. It's simple.
5.) And as Always, Thou Shalt Not Be a Dick-
Be conscientious, do what you can to help out others; and make sure to have fun. That's the point of the game. To loose sight of that, would be a real shame.