Dindio is an open-source toy with infinite ways to play. You can try the three example games here, modify them, or come up with your own Dindio games from scratch!

example game 1:
Two or more players each choose a color of little ninjas. Everyone tries to kill (knock down) other player(s)' little ninjas by taking turns to use the big ninja: you drop his head into the ninja castle at the center and he will jump back out to kill the little ninjas! Once a player's little ninjas are all killed, he is out of the game. The remaining players continue to take turns until the last survivor wins.

example game 2:
Two or more players all try to hit the blue ninjas and avoid the red ones. If a red ninja is knocked down, the kill doesn't count and all red and blue ninjas hit in this turn must be put back up. At the end the person having killed the most blue ninjas wins.

example game 3:
Two or more players each choose a color of ninjas and try to indirectly kill them by hitting the red ninjas first. The red ninjas are put back after being used each time. A player wins once all ninjas of the color he/she picked have been killed. The remaining players can continue until only one is left.

For all three demo games, the little ninjas are set up roughly 7" away from the outer surface of the castle (applies to blue ninjas in game#2 and red ninjas in game#3). You don't need to be too precise since this range is quite forgiving thanks to the big ninja head! Your Dindio may have a different range than mine and you can find out by simply doing a few test knockings.

Below is how you can make your own Dindio:

Step 1: The Big "ninja" - Head

All materials and tools I used to make Dindio are bought in a local art supply store. All sizes are standard sizes you can buy.

You need:
a Foam Ball, diameter = 2.875" (2 and 7/8 inches)
a Dowel, diameter ≈ 5/8", length ≥ 4.25"

I used:
a Durafoam Ball
a Hardwood Dowel cut to 5" for easier handling

You do:
Make an approximately 1/2" deep hole on the foam ball towards the center by simply pushing the dowel into it.

Step 2: The Big "ninja" - Body

If you don't want to make it look like a ninja, ignore all the "black"s in this step and all following steps.

You need:
a piece of Print Paper + Black Colouring Pen or Black Color Paper, width ≥ 4.25", height ≥ 3"
Double-Side Tape or Glue
Black Tape or Tape + Black Colouring Pen

I used:
a piece of Black Color Paper, width = 8.5", height = 11", (U.S. Letter size)
Double Side Tape
Black Masking Tape

You do:
Cut the paper into width = 4.25" and height ≥ 3". If your paper is in U.S. Letter size, you can simply fold it in half along the longer edge and cut the folding line to get a piece of 4.25" x 11", which is what I did.

Use the same dowel used in step 1 to roll the paper into a 4.25" high cylinder and keep the form by applying black tape or / and double-side tape or glue along the edge.

Tape the ends of the cylinder with black tape for a tighter fit into the "ninja head" later. If you didn't use black paper and black tape you can now paint it black.

Attach the "ninja body" (paper cylinder) into the hole on the "ninja head" (foam ball) made in step 1. Adjust the thickness of the tape if needed.

Step 3: The Big "ninja" - Face

You need:
Black (and White) Paint

I used:
Black and White Acrylic Paint

You do:
Paint a "ninja face" on the "ninja head". The "ninja body" is handy to grab while painting. White paint helps but is not necessary since the foam ball is white. You can design your own "ninja face" or whatever I want it to look like!

Step 4: The Big "ninja" - Foot(feet?)

You need:
Black Plasticine or Clay

I used:
Black Plasticine

You do:
Cover the other end of the "ninja body" with black plasticine. Make it a rounded form. Make sure the overall height of the "ninja" is approximately 6.875" (6 and 7/8 inches).

This height is crucial for the toy to work. It can be checked once the ninja castle is finished in step 8 and then adjusted easily due to the forgiving property of plasticine.

Step 5: "ninja Castle"

Skip to step 7 if you don't have access to a cutting machine.

You need:
Cardboard Tube(s), inside diameter = 3"
Cutting machine such as Bandsaw
Cardboard or Thick Paper
Glue

I used:
Cardboard Mailing Tube
Bandsaw
Black Cardboard
White Glue

You do:
Cut out two tube of heights described in the image. Clean the edges with scissors or a knife if they are rough from the bandsaw cut.
Cut out a circle of cardboard matching the tube's profile.
Stack the two tubes together with the cardboard circle in between as shown in the image. Align and glue them.

Step 6: "ninja Castle"

You need:
Some weighing material

I used:
The same Black Plasticine used for "ninja foot" in step 4.

You do:
Attach the weight to the inside of one half of the "ninja castle". I pressed some of the black plasticine used for "ninja foot" in step 4 onto the inside wall of one of the two tubes.

Skip step 7. Go to step 8.

Step 7: "ninja Castle" - Made With Tapes

Skip this step if you did step 5 and 6.

You need:
Tapes, inside diameter = 3", width = 15/16" or/and 30/16" (see image)
Cardboard or Thick Paper

I used:
two 15/16" Masking Tapes + one 30/16" Duct Tape
Color Paper

You do:
Cut out a circle of cardboard matching the tape's profile. Stack the tapes and the cardboard circle in any one of five configurations shown in the image. Tape them together.

Step 8: "ninja Castle" - Facade

You need:
Paper
Anything you can draw with
Double-Side Tape or Glue

I used:
White Print Paper
Black Marker
Double-Side Tape

You do:
Cover the "ninja castle" with paper and draw some ninja castles on it. You can design your own "ninja castle" or whatever you want it to look like!

Now you can test if the big "ninja" will come out of the castle and flip over when his head is dropped into the castle (see the video demo on the 1st page). Experiment with the size and form of the plasticine "foot". It should be fairly easy to find the sweet spot.

If you choose to use existing objects as the targets instead of "little ninjas" made of paper, you are done! Enjoy your Dindio!

Step 9: Little "ninjas"

You need:
Color Papers or White Paper + Colouring Pens
Double-Side Tape or Glue

I used:
White Paper + Color Markers
Double-Side Tape
the same Dowel first used in step 1

You do:
Choose what colours and how many of each color you want your little "ninjas" to be based on your games. Cut the paper based on how big you want the "little ninjas" to be. I horizontally cut letter size print papers into halves.

Roll the color paper or coloured white paper into cylinders and keep the form with double-side tape or glue. You can but don't have to use the same dowel used to make the big "ninja". Since size doesn't matter this time, you can do the rolling with a cylindrical pen or even with bare hands.

Step 10: Little "ninjas" - Face

You need:
anything you can draw with

I used:
a black pen

You do:
Draw some ninja faces on the little "ninjas"!

Done!
There is no instructable on how to design your Dindio games! That's too easy. Just think and play!
And let me know what you come up with!