Continuity

Red Dwarf is particularly known for its creators' lax attitude towards continuity. As such, there were many facts and events that go contradicted (sometimes multiple times) from series to series. In the beginning, changing such things as the number of people on-board the ship (Originally 169, later became 1169), the number of times Rimmer took his astronavigation exam, or even what century Lister was from (In the 1st & 2nd series Lister was from the mid 21st century, but in the series 4 episode "Justice" Lister claims to be from the 23rd century), was a result of Grant and Naylor not bothering to check their facts because they assumed that no-one else would either. Perhaps the best-known example involved Lister having been said to have already had his appendix removed in an episode in series II, only to suffer from peritonitis and have it removed during series VI, an error that has received numerous attempts at explanation by writers and fans alike (most famously during the Smeg Ups video, when Kryten declared that Lister "liked the operation so much, he decided to have it again"[13]). Once the show began to attract a quite large fan base, however, such errors began to be gleefully pointed out by fans the world over, to the extent that they became one of the series' most notable features. Most of the series' continuity errors are therefore now treated with a certain amount of tongue-in-cheek reverence, and cheerfully ignored (just as Grant and Naylor ignored them when writing the show).