Shade some cells black so that the black cells form the shapes of twelve different pentominoes. Each pentomino shape is used exactly once, but can be rotated or reflected. Pentominoes cannot touch along edges, but can touch at corners. If a corner is marked with a dot, then two pentominoes touch at that corner. If a corner is not marked with a dot, then two pentominoes do not touch at that corner.
(Rules from PGP IB, example (5 tetrominoes) from Belarusian Puzzle Championship 2010)
- Touching Tetrominoes: Place all tetrominoes. They can be reflected in some rules and cannot be in others.
History of the puzzle
Invented by Vladimir Portugalov (Belarus) in 2010 under the name "Пентакасание" ("Penta Touch"). First appeared on Belarusian Nationals 2010.
Sometimes the puzzle appears under the name "Pento-Blokus," after Blokus, a popular board game released in 2000.