Logic Masters Deutschland e.V.

This is my first sudoku puzzle, with a custom ruleset. It takes inspiration from this game, where you rotate tiles to connect waterflow. Familiarity with the game will help, but is not necessary for solving.

Main puzzle

Play on Sudokupad (Cog icon > "Enable Pen Tool" to draw lines)

Rules:

Normal sudoku rules apply.

Counting Circles: A digit in a circle indicates how many of the same digit are in circles.

Killer Cages: Digits in a cage sum to the indicated total.

Plumbing: Every cell in the grid contains "pipes" connecting it orthogonally to at least one of its neighbours (horizontally and/or vertically, but not diagonally).

There are 4 types of plumbing cells:

• O-shape: The circles are endpoints; each circled cell is connected to exactly one neighbour.
• L-shape: Connected to exactly 2 neighbours at a right angle, it must contain a (L)ow digit (123).
• I-shape: Connected to exactly 2 neighbours in a straight line, it must contain an (I)ntermediate digit (456).
• T-shape: Connected to exactly 3 neighbours, it must contain a (T)remendous digit (789).

The pipes form a single connected graph, which may branch but cannot loop, contain loose ends, or exit the grid.

Training puzzle

Here is a small training puzzle for the "plumbing" rules. It's an easy 1 star difficulty.

There is no killer cages nor counting circles. Instead, the circles must contain an Odd digit.

Play on Sudokupad or View solution

Rules for training puzzle:

Normal 6x6 sudoku rules apply.

Plumbing: Every cell in the grid contains "pipes" connecting it orthogonally to at least one of its neighbours (horizontally and/or vertically, but not diagonally).

There are 4 types of plumbing cells:

• O-shape: Connected to exactly one neighbour, it must contain an (O)dd digit.
• L-shape: Connected to exactly 2 neighbours at a right angle, it must contain a (L)ow digit (1 or 2).
• I-shape: Connected to exactly 2 neighbours in a straight line, it must contain an (I)ntermediate digit (3 or 4).
• T-shape: Connected to exactly 3 neighbours, it must contain a (T)remendous digit (5 or 6).

The pipes form a single connected graph, which may branch but cannot loop, contain loose ends, or exit the grid.