Rules -- Bridged Series

Bridged Series was invented by the Japanese puzzle company Nikoli (under the name Hashiwokakero).

1. Draw horizontal and vertical bridges (diagonal bridges are not allowed) between the islands according to the following rules.
2. A number on an island indicates how many bridges are connected to that island.
3. At most two bridges can connect a pair of islands.
4. A bridge may not cross over an island or another bridge.
5. All of the islands must be connected via the bridges. (It must be possible to get from any island to any other island using the bridges.)

Rules -- Solomon's Keep

Solomon's Keep was invented by the Japanese puzzle company Nikoli (under the name Five Cells – that's a transliteration, not a translation, believe it or not).

1. Divide the grid along the grid lines into pentominoes (regions containing exactly five cells each).
2. A number in a cell represents how many edges of that cell are borders of pentominoes (including the perimeter of the grid).

Rules -- Ellbound

Ellbound was invented by the Japanese puzzle company Nikoli (under the name Sashigane, which refers to a carpenter's square).

1. Divide the grid into L-shaped blocks, each consisting of an elbow, a horizontal arm extending from the elbow to another cell in the same row as the elbow, and a vertical arm extending from the elbow to another cell in the same column as the elbow.
2. A cell with a circle in it is the elbow of its corresponding block. If the circle has a number in it, that number represents how many cells are in that block.
3. A cell with an arrow in it is the tip of one of the arms of its corresponding block, and the arrow points to the elbow of that block.

Rules -- Dominnocuous

Dominnocuous was invented by the Japanese puzzle company Nikoli (under the name Norinori).

1. Shade in some cells such that every region contains exactly two shaded cells, and every shaded cell shares an edge with exactly one other shaded cell.

Rules -- Proof of Quilt

Proof of Quilt was invented by the Japanese puzzle company Nikoli (under the name Shakashaka) in 2008. 

1. Place black isosceles right triangles in some of the white cells in the grid. Each triangle must occupy exactly half of its cell, but may be in one of four orientations (◢, ◣, ◤, or ◥). A white cell may only contain one triangle.
2. Every contiguous region of white must be shaped like a rectangle (or a square).
3. A number in a black cell represents how many triangles share an edge with that cell.

Rules -- Spirits of Serpentine

Spirits of Serpentine was invented by the Japanese puzzle company Nikoli (under the name Hebi-Ichigo) in early 2009.

1. Locate several snakes in the white cells of the grid. Each snake consists of five cells, numbered 1 (the head) through 5 (the tail). Consecutively numbered cells within a snake must share an edge.
2. No two snakes may overlap or share an edge.
3. No snake may see another snake. A snake's eyes are on the side of its head opposite the number 2 cell. It can only see in that direction, in a straight line, up to the edge of the grid or the nearest black cell (whichever is closer). (See this illustrated example.)
4. A cell containing a number and an arrow represents the first number encountered in the row or column pointed at by the arrow, up to the edge of the grid or the nearest black cell (whichever is closer). A 0 means that no snake is encountered in this area.

Rules -- The Inner Limits

The Inner Limits was invented by the Japanese puzzle company Nikoli (under the name Bag, although the name Corral is probably more well-known amongst the global puzzle community).

1. Draw a single loop along the grid lines. The loop may not cross itself or branch off. In other words, the interior of the loop will be a single polygon.
2. Every number must be contained inside the loop.
3. A number indicates how many grid cells, including the cell itself, lie in an uninterrupted horizontal or vertical line from that cell, up to the nearest edges of the loop.