Pokedoku takes the grid logic of Sudoku and mashes it with Pokémon trivia. Instead of filling a 9x9 grid with numbers, you are usually presented with a 3x3 grid. The rows are defined by Pokémon types (e.g., Fire, Water, Grass) and the columns are defined by generations (e.g., Gen 1, Gen 2, Legendaries).
For example: