Here’s something new, a puzzle I made when a friend asked for “something with pipes”. I think the general idea of finding a pentomino net works quite well, though I’m not convinced of the details of the mechanics in this version. In particular, some other kind of clues might work better, e.g., giving the connection dots.

**Edit** Amended the rules to hack the puzzle to uniqueness.

**Rules** Place a full set of pentominoes onto the grid lines. (Each pentomino cell maps to a vertex, and adjacent vertices are connected by an edge, like the clues from Puzzle 82.) Each edge may be part of at most one pentomino. If two pentominoes touch at a vertex, there must be exactly two pentomino edges touching that vertex. There must not be any vertices with a single edge.

Wherever a vertex is marked by a letter, that vertex must be one of the five vertices of the pentomino corresponding to that letter. There may be still be a second pentomino using that vertex.

Pentominoes may be rotated and mirrored. Except F: F may be rotated but must be oriented as in the example solution.

**Example** with pentominos F, U, V, Y.

uvoIn my solution, the F can be mirrored.

robPost authorEven in the example… Thank you. Don’t think I’ll try to really fix it.