1. A letter placement game, comprising: a puzzle grid having a plurality of cells, a plurality of horizontal rows, a plurality of vertical rows, and a plurality of subgrids, each subgrid, each horizontal row, and each vertical row having an equal number of cells; a predetermined set of characters, the puzzle grid comprising filled cells, each filled cell comprising one of the characters, and the puzzle grid comprising empty cells, each empty cell associated with a predetermined solution character; clue input comprising a plurality of clues, each clue having a solution to each clue based on the predetermined set of characters, each clue associated with a predetermined location in the puzzle grid, each predetermined location associated with a predetermined number of the cells, each predetermined location having a contiguous association of the cells of each predetermined location, each clue solution having a set of solution characters corresponding to the predetermined number of cells associated with each clue, each clue solution having a semantic meaning; character singularity rules requiring that each (i) horizontal row contains one set of the predetermined characters having one instance of each character, (ii) each vertical row contains one set of the predetermined characters having one instance of each character, and (iii) each subgrid contains one set of the predetermined characters having one instance of each character; and a puzzle solution for the puzzle grid, each character in each set of solution characters conforming to the character singularity rules, and each solution character for each empty cell conforming to the character singularity rules.