This is the first of a three-part series of essays on crossword puzzles. I recently realized that I don't often think about crossword puzzles as puzzles : as problems to solve. When I picture a crossword, I think of the beautiful completed grid, the pattern of interlocking words and black squares. Perhaps because I've been focusing a bit more on construction, I haven't thought of crosswords much as an experience from the solver's perspective. So, here are some observations that might be trite or obvious, but were new to me: A crossword puzzle is a series of questions. Questions are trivia (testing knowledge/memory) or riddles (with wordplay and misdirection), or both. At the start, you only know each answer's length in letters. The questions vary considerably in their difficulty. You may get some answers immediately, and others after some thought. However, even in an easy puzzle, many questions are initially difficult, and might truly be impossible , due to having