I have two versions, one that practices the NH2 "I know how to"/"I can show you where to"/etc. grammar, and one that practices the NH3 grammar that is similar "Tell me what ~ is." I made a powerpoint for each that helps you explain how to play. I have also attached a warm-up powerpoint for the 3rd grade version.
Materials:
Worksheets (one per group)
Dice (at least four)
Cards
Computer
TV
Prep:
Cut out the colored cards and mix them up. Cut the deck in half and give half to the JTE.
Have students play janken in their groups to decide order. Give one card and one worksheet to each group but tell them not to look at the card yet.
HOW TO PLAY (if you follow along with the powerpoint it should all make sense):
In order, one student takes a card (at first, it's just the card in front of them), then writes their name and what's written on their card on their worksheet. If they understand what's being asked, they go to the ALT or JTE and try to perform the task. For example: "I know what to use in winter." "It's a kotatsu."
If they could complete the task, they can roll a pair of dice, then choose one. On their worksheet, the JTE or ALT writes the number next to the task they did, and checks a box in the grid at the bottom. Ex: If they rolled a 1 and 5 and chose 5, write 5 next to their task and check one of the boxes below 5 in the grid.
The student takes a new card from the pile and brings it back for student #2 to write and try the task.
CALCULATING SCORE:
One check in the grid is one point.
If they get a vertical (縦 - たて - tate) 3 in a row, they get 3 points.*
If they get a horizontal (横 - よこ - yoko) 6 in a row, they get 6 points.
I like to play that if they get three of a number, they can't get any more checks for that number. This can help keep the fast/advanced groups from getting *too far ahead.
IF THEY CAN'T COMPLETE A TASK:
They can pass and take a new card, but the JTE/ALT will cross off one of their exchange (取替 とりかえ tori-kae). They can only do this three times.
I've played this for as short as 10 minutes, but it wasn't as effective and there was a bigger gap between fast/slow groups' scores. I recommend a minimum of 15 minutes, but once I played for 20 minutes and the kids weren't ready to stop so we just shuffled cards and played for 10 more minutes. I imagine you could play for longer.
For me, the mix of verbal explanation with visuals on the screen was pretty effective for conveying the rules, but I'm open to advice on how to make it clearer!