“ After building a new granary,it is customary to let a rat feast on grain. After that,there is chase and the rat is killed. Failing to catch this rat is a bad omen.”
“ A world where, instead of aging in years, the people age in knowledge. So, instead of dying once a general age was reached, they die once they achieve a certain amount of knowledge. A man could live forever if he never learned anything, or could die after reading a few choice books. Of course, the knowledge of the land would be regulated, like medical drugs.”
“ A known immortal traveling with the PCs kills an attacker, and is arrested and charged with murder, since immortals cannot kill in self defense, being immortal.”