Author’s note: I did all the diagrams in MS Paint so please excuse the rough edges. I would also like to say that the inspiration for this sub came straight after reading Mageek's mirror motion puzzle.
What is it?
It is a puzzle of Chinse origin that is composed of only 7 pieces including:
- 2 large pieces of right angle triangles
- 1 medium piece of right angle triangle
- 2 small pieces of right angle triangles
- 1 small piece of square
- 1 parallelogram piece
In Figure 1 below, I show the 7 pieces in their 'default' configuration with each piece denoted by a different colour.
It really came about as a toy for children. The basic premise is that they are presented with an outline of a particular shape (say that of an animal) for them to assemble using all of the 7 pieces. The name tangram apparently came from the Chinese character tang referring to one of the most prosperous dynasties in ancient China (the Tang dynasty) and the Greek word gramma with similar meaning to the word graph in English. In Chinese, its name is Qi Qian Ban or the Seven Boards of Skill. For more details, refer to the Wiki here.
Figure 1: the 7 pieces forming a square (its 'default' configuration when first bought in a pack)
Incorporation into Gaming and Difficulty Levels:
Such a puzzle can be easily inserted onto any cask, door or wall to be found in a dungeon as long as the object involved is large enough to fit in a panel showing a shape outline. A natural way to tweak the difficulty level is of course to introduce time limits and/or increasing the number of puzzles that have to be solved in one go. However, one can also create different difficulty levels by varying the conditions under which the actual puzzle pieces are attained.
Easy- The puzzle pieces are found in direct proximity to the panel showing the shape outline or found earlier on as random loot from monster encounters or through other ways involving little effort on the part of the PCs.
Medium- A minor puzzle has to be solved before the puzzle pieces ‘pop out’ via a hidden mechanical device or magic
Hard- The puzzle pieces are found on the body of the cask/door/wall to which the panel is attached to but are hidden as part of the artwork painted/tiled on there. I picture two sub-levels here with the easier version being that the pieces are hidden in an oil painting as part of jewellery, a crown, floor tiles, corner of a vase etc. and the truly devious version being that they are hidden in an artwork composed entirely of triangles and squares.
For more examples, visit here