Broom is a one-player card game. There is no skill involved, yet it is addictive.
Take a shuffled deck of cards. Hold it, face down, in one hand. Place a card, face up, on the floor next to the left wall of the room. Place another card, face up, to the right of it, and a third to the right of that one. If the first and third cards are the same value or the same suit, then pick up the middle card and place it on top of the first card. Move the cards closer together if need be. Place another card to the right, if this one is the same value or the same suit as the card 2 places before it, take the card in the middle and move it one place to the left. If, after moving the card, there is another set of three so that the two end ones are the same value or suit, move the middle card to the left. Place cards from the deck, one by one, to the right of the line, and follow the simple rule: wherever there are three consecutive cards (or piles of cards), and the cards on top of the two end piles have value or suit in common, place the middle pile on top of the left one. (Periodically, you will have to condense the line because many wide gaps will form the longer you play.) You win if, after you have placed the last card from the deck on the floor and moved cards according to the rule, you end up with only two piles. Be warned: very very few games will win, unless you cheat by manipulating the deck.
When actually playing, it is impractical to make a long line left-to-right. Easier to manage is starting on the far left corner of a table, moving the line right, then moving down when you reach the end of the table and going right-to-left on the second row, then left-to-right on the third row, etc. - like a snake. In this case, of course, you do not always move the middle pile 'to the left', you move it towards the start of the line.
This is a most excellent game because it surprises you. A long string can very suddenly and unexpectedly collapse with a single card added to the end - a chain reaction occurs in which moving one pile opens up one more move, again and again. If you play enough times, you'll get a single move which collapses a string of 20 or more piles into a single pile; these are the moments you play for, and it feels great (this is what makes it addictive). The best thing about the game is, if you have a really spectacular game, pick up the last pile and put it on top of the next one, pick that up and put it on the next one - collect all the piles in order, and you can play exactly the same game again!