Crozzle is a mixture of jigsaw puzzle and crossword. Given a 100 or so words you place them into a grid that is blank.
The grid size was 15x10 grid until 1994 when it became a 15x13 grid.
Scoring
10 points per word and points for each interlock (intersection of words):
Letters
Score
ABCDEF
2 points
GHIJKL
4 points
MNOPQR
8 points
STUVWX
16 points
Y
32 points
Z
64 points
Rules
All placed words must fit completely within the grid.
The intersection of two words must be at a shared letter. We call these intersection an interlock
No two words may be adjacent unless the adjacent parts are covered by rule 2 or placed end to end.
All placed words must interlock with at least one other word in the grid.
Not all of the words need to be placed.
Crozzle As Graph
You can see crozzle as a graph of connected words. This demonstrates how duplicates can arise through the cyclical nature of the graph.
Here is an example of some solutions as graphs: GraphTheory.pdf