Rules (from Grant Fikes's blog): In this Room and Reason [Heyawake] puzzle, a room with an S in it must have 180-degree rotational symmetry, and a room with an A in it must NOT have 180-degree rotational symmetry. The rules are otherwise unchanged.
Shade some of the cells so that the grid is divided into white areas. Each white area
must contain exactly one number and that number must be the size of the white area it
is included in. Cells with numbers cannot be shaded.
This is a Panoramic Skyscrapers puzzle. Standard Skyscrapers rules, except that clues are given between two rows or columns. These clues give the sum of the Skyscrapers clues of the two rows/columns they border. I first saw this variation on the 2016 USPC written by Michael Rios; I'm unsure if it has been done elsewhere.
This is an All Threes Slitherlink puzzle. Rules (from Palmer Mebane's blog): This is a Slitherlink puzzle, with a twist. Every 3 in the puzzle is given to you. That is, if the solution has three segments around a single grid square, there is a 3 in that square.
Rules (from IB): Locate a snake (a 1 cell-wide single continuous path) in the grid whose head and tail are given. The snake does not touch itself, even diagonally. Numbers outside the grid indicate the number of snake cells in that row/column. Numbers inside the grid indicate how many of the 8 cells around it are used by the snake. (The O's mark the head and tail of the snake in this puzzle formatting; in the IB, they are marked by black circles.)