[edit]Done with this. Check the remix, the new interlocking tile. Not universal anymore, though.

This is a first attempt at a blank jigsaw piece that can connect at every side to copies of itself.

The intended use is for scrabble - locking pieces mean they won't get scrambled so easy. Hence the interlocking parts at all sides.

Naturally it shouldn't be used on its own - would be rather boring :-D

I tried to find something like it, but didn't find anything. Either it doesn't exist or I fail at searching...

[edit] One problem just popped up - apparently it's not possible to connect four pieces into a square...

I knew there's something I didn't see :-D

Well, that's why it's tagged Work in Progress.