Iain M Banks' First Two Culture Novels

A game plays a major role in the first novel and the second is all about gaming. Is it valid to make games so important in the stories without telling the reader any of the rules of these games? Despite not doing this, Banks does convey what it feels like to engage in gaming.

The Culture is a sustained presentation of a wealthy, high tech, easy-going, interstellar civilization whereas the Empire in the second novel is systematically more callous than any human society.

There is a fascinating ecology on the planet Echronedal:

oceans at the poles;
land around the equator;
a fire that moves permanently around the land;
organisms that have adapted to survive and thrive in these conditions;
an Empire that considers it appropriate to game in fire-proof castles on the surface.

I cannot help thinking that "hard sf" staples like hyperspace are really not sf but fantasy, especially when human beings from the Milky Way galaxy encounter in the Lesser Magellanic Cloud beautiful women with whom they can have sex.