My Hnefatafl set has circular pieces on a square board. I quite like the rectangular board and rectangular pieces of https://www.instructables.com/id/Design-and-Build-Your-Own-Hnefatafl-Game-Board/

The pleasant thought of sitting on a couple of upturned logs playing Hnefatafl on a board carved into the end of a larger log along with the World Tafl Federation logo put me on the path of creating a round Hnefatafl board. In hindsight it seems obvious, but it took quite a few sketches to work out what needed to happen along the diagonals.

See 11x11Morph GIF

I thought something might exist for chess, but most circular boards played differently. I eventually found https://www.chessvariants.com/shape.dir/chess_in_the_round.html It doesn’t seem to have caught on in the chess world, but why should that dissuade me from creating a version for Hnefatafl?

After creating a playing board sized for my pieces, I didn’t have any logs of that size. When my frozen pizza came with a circular piece of cardboard reinforcement, I thought it might be an answer. It was a bit smaller than I had originally envisioned, but a bit of crowding seemed okay.

Supplies

Round piece of cardboard

Printout of the round Hnefatafl board, sized for your cardboard.

Pencil

Compass

Fine-point Marker

Straightedge

Chisel-tip marker

Step 1: Centering on the Cardboard

The original template was printed on two pieces of 11” by 17” paper, taped together. My current printer is only able to accommodate 8.5” by 11” (letter) paper, so transferring the layout was perhaps not as straightforward as it might have been.

I sized the original image to the size of the cardboard, then cropped out everything that wouldn’t fit on letter paper.

I centered the original template on the cardboard then folded it on the diagonal to make room for the folded letter-sized template.

Step 2: Laying Out the Circles

Once the template is centered, mark the center and the radii for the five circles.

Use a compass to draw the circles in pencil.

I tried not to, but I was a bit heavy-handed and ended up with a hole at the center.

Once drawn in pencil, follow up with a fine-point, permanent marker.

Step 3: Laying Out the Straight Lines

Trim around the outside of the template to make marking the outside edge easier.

Mark along the outside and along the diagonal then connect the dots.

Turn the template over and repeated the process to complete one quarter. You only have to mark the outside, because the lines will meet along the diagonal.

Repeat for the rest of the board.

Step 4: Marking the Starting Positions, Center, and "corners".

Most playing boards have indications for the starting positions. I kept it simple with circles for the defenders and darkened circles for the attackers. The end of a pencil worked well as a template as did eyeballing the location. Get it right with pencil then go back over with a permanent marker. Switch to a chisel tip marker for filling in the circles.

For the king's square in the center, I went with a variation of a four-cornered (quaternary) Celtic Knot. I didn’t show the over/under, but it is a figure you can make without picking up your pencil. When the same pattern is morphed into the corner, it somewhat resembles a bird. I like the king/bird paralleling the Odin/raven connection of Norse mythology. Again, get it right in pencil then go back over with a permanent marker.