For slots, I'd choose an illustrated paytable every time. Seeing a wild symbol beside its explanation makes it much easier to remember, and I enjoy finding out how the animations connect with the game's theme. Blackjack calls for a different approach: an example hand can demonstrate hitting, standing and the dealer's actions very clearly. The game descriptions linked through https://shelbywin.uk/ cover several styles, including familiar slots and table games, so I find it worthwhile to read the individual rules instead of using one explanation for everything. Starburst is a nice example of a recognisable slot with a distinctive expanding-wild feature. A good rules page adds to the enjoyment of understanding its design.