You never have the right to kill a player later, if that player attacked you while defending their home city or council.

This goes for formal and informal raids. Formal raids being described in HELP RAIDING. Informal raids are when you enter a city you are enemied to, for any reason at all.

If you are an enemy to a city, enter that city, and are attacked or killed, even if you have not attacked anyone while there, you are considered to be raiding. You cannot seek retribution on the player or players that attack you while in an enemy city.

However, you may attempt to kill anyone that attacks you while you are in an enemy city. However, as stated above, you cannot try to kill them later.

If the defending player decides to continue attacking you outside of the city, or attempts to kill you later for raiding their city, you are then allowed to seek your revenge.

I hope that is clear enough for everyone.

Penned by my hand on the 25th of Artificium, in the year 141 AM.