The file has 4 pages, which makes about one set of dominoes. I recommend about 4-5 players per group, so you should print out enough copies according to your class size.
Print out the dominoes (and laminate if possible).
Cut along the solid black lines. DON'T cut the dotted lines. Each domino should have 2 squares, with two pictures/words that face outward from that dotted line.
Students shuffle the dominoes and pass out about 5 to each group member. The rest of the dominoes become the deck in the center of the table.
Students play janken to decide who goes first.
Students must connect the same Halloween characters together, both picture-picture, picture-word, or word-word. For example, "black cat" can only connect to other "black cat"s. Students can lay down as many dominoes as they can per turn. As students lay down the dominoes, they should say the words.
If a student cannot lay any dominoes down during their turn, they should draw +2 dominoes from the deck.
The first student to lay down all of their cards is the winner.
(Usually I let students connect dominoes from any direction, so that each picture in theory can accept 3 other dominoes, but you can change this up so each picture gets connected to only once if you want the rounds to take longer.)
I've played this activity from 4th grade through 1st year JHS. For younger students, I think it is best to have flashcards on the board so they can check the letters with what's in their hand. They can also ask you to read the card, or ask their friends to help them read each domino. For older students, they usually can figure out the words on their own.