You will need dictionaries for each group, and some dice.
Keep going as long as they are enjoying it, which can quite conceivably be all lesson.
Similarly to the Typhoon Game or Snail Salt Chopstick Attack, Snake Eyes involves drawing as many snails or houses on the board as possible. In fact, any certain-number-of-strokes picture is fine. You could use the kanji for English or something else, or an image of some sort. I find the snail and house to be pretty straightforward.
- Make groups. The ideal size is between 2 and 6 students.
- Give each group a dictionary.
- Have at least two dice on the table at the front of the class. Two for you and two for the JTE is better. Big soft ones from the 100 yen store are ideal and don't get lost.
- Write up group numbers or names on the board with space for them to draw next to.
- In their groups, students must make a sentence using the dictionary (if necessary). It can be any sentence they want, as long as it uses the target grammar.
- One student from the group comes to you or the JTE and tells you their sentence. If it's good, they can roll the dice, if not they must go back and try again.
- I did "Why don't we..." today, and if I or the JTE wanted to do what they suggested, they could roll two dice, if not, only one.
- It's up to you how you award the dice rolls. You can have bonuses for great sentences etc.
- Numbers on the dice equate to points. One point = one line on their way to drawing a snail or house (which take nine lines to draw).
- One dot on the dice means they have to erase all their drawings.
- One dot on both dice is SNAKE EYES, and means they can erase all of another team's drawings.
Laura and I came up with this one, although she probably deserves the most credit. Feel free to use it, but please don't redistribute anywhere else.