There are two different kinds of sin that the player can obtain, which have different consequences and means for removal.
One type of Sin is a value that determines if it is possible for a member Blade of the Darkmoon covenant to invade the player when using the Blue Eye Orb. Once a player obtains this kind of Sin, their username is entered into the Book of the Guilty, and will remain there until the Sin value returns to zero.
The other Sin refers to whether or not the player has made NPCs hostile towards the player. This type of Sin is not logged in the Book of the Guilty, but is instead informed to the player by Oswald of Carim, by allowing the player to pay for absolution.
Obtaining "Book of the Guilty Sin"
There are two ways to become logged in the Book of the Guilty.
- Receive an Indictment from another player online after a match of PvP
- Getting kicked out of a Covenant
Each time this occurs the player will receive one point of Sin.
Removing "Book of the Guilty Sin"
The only way to lose this sin is to be invaded by members of the Blade of the Darkmoon covenant. Each time the player dies during a PvP match with a Blade of the Darkmoon, their sin count will be reduced by one. This happens regardless of what killed the player, or if the invader had any part in their death.
When this score returns to zero, the player will no longer be a target for Blue Eye Orb invasions.
Obtaining "NPC Hostility Sin"
Angering any non-hostile NPC will trigger this type of sinner status on the player. Unlike the Book of the Guilty, it is not accrued and there is no distinction between angering one NPC or many. There are two ways to anger NPCs:
- Aggro an NPC by attacking them and removing over 10% of their HP
- Anger a covenant leader by doing something against their approval
Removing "NPC Hostility Sin"
This sin can be cleared by paying Oswald of Carim a fee for absolution. The cost of absolution is 500 souls per level, meaning a level 50 player would have to pay 25,000 souls.
Clearing this Sin will cause aggro'd NPCs to become friendly again, and unwelcoming covenants will allow the player to rejoin.
- Though paying for absolution will allow the player to rejoin covenants in most cases, the Darkwraith covenant cannot be rejoined if Darkstalker Kaathe is angered and leaves, as he won't return.
- If Petrus is killed prior to Reah and her companions moving to the Tomb of the Giants, they will attack the player on sight. They will remain hostile for the rest of the game, even if the player's sins are absolved by talking to Oswald.
- Though having no "Book of the Guilty Sin" means that Darkmoon invaders cannot invade players through the Blue Eye Orb, they may still invade players in Dark Anor Londo using the Darkmoon Blade Covenant Ring. This type of Darkmoon invasion does not require the host to have any Sin.