Pagat is a great simple database of games that can be played with normal decks of cards and dominoes. It is a fantastic resource for looking up the rules to games you can’t remember that somebody taught you.

Also see

https://www.pagat.com/alpha/

https://www.pagat.com/domino/

https://www.pagat.com/solitaire/card.html

https://www.pagat.com/class/#equipment