“ The Californian Sea Otter, as a species, eats about 30 different types of food found throughout its range. Each individual otter, however, will only eat 3 or 4 of these foods - those it was fed by its mother as a child. It will not eat the others even if failure to do so means it would starve. Maybe other, possibly larger and more dangerous creatures and monsters, have similar habits.”
“ Pick up a pathology/microbiology book, and add the diseases/syndroms to your game. Your players will freak out.
Coughed at? Diphteria. or tuberculosis?
Drunk from a muddy stream? Or just walked through? Well, let us introduce you to schistosomiasis...
Hit by a stream of energy? Too moch mana is ust like too much radioactivity - perhaps all mages could develop cancer early if too powerful...”
“ A kingdom where, if there are multiple princes (princesses can't rule unless they have no siblings), the princes fight to the death in the arena to decide who gets to rule. A simple way to make sure your brother cannot make a bid for the thrown, and keeps the royal blood in one line.”