Has an AFL game ever ended 29-18?
Exactly once. On June 2, 1900, Essendon beat St Kilda 29-18, and no AFL game before or since has ended that way. When it happened it was a scorigami, the first 29-18 in league history.
That makes 29-18 the 3836th most common final score out of 6,607 that have ever occurred in AFL. One point away, 30-18 has happened 2 times and 29-19 has happened never.