Many shows have some form of structure to their seasons, rather than just being [[GenreAnthology collections of stories.]] This article mostly assumes that the series in question are US full-length series of around 20-26 episodes with some to low SeasonFluidity. Even in cases of BritishBrevity, the season opening and closing episodes will tend to be similar in style to those in the US, regardless of the season's length.


[[folder: Season Opener: ]]

This will often be big and spectacular, to lure viewers back to the show. It is not uncommon for new characters to be introduced to the show or for major plot changes to take place. See also {{Premiere}} and {{Pilot}}. It is also one of the most likely places to find a double length episode (and even when the first two episodes are both normal length, it's not at all uncommon for networks to show them back to back).


[[folder: Lucky Episode 13: ]]

Some series only have the first 13 episodes of the first season commissioned, [[Front13Back9 with the promise of more if it is successful]]. For this reason, the writers will work out a 13-episode arc plot so that if the series is not renewed, it will still have a satisfying ending. If it ''is'' renewed then they need only rewrite the [[SeriesFauxnale final script]] or so to introduce another threat or more plot threads.


[[folder: The Ep- 15 Shift: ]]

Episodes 15-16 of a season tend to fall around the time of (February) UsefulNotes/{{Sweeps}}, so networks will have big spectacular episodes to attract viewers. Plot shifts are not uncommon here, as these are the early installments of the "[[Front13Back9 Back 9]]" extension.


[[folder: Season Finale (Ep- 20 to Ep-26): ]]

Again, big and spectacular, usually tying up all of that season's emotional and plot arcs, although an end of season CliffHanger is possible. There may well be character departures by various different means. In cases where the season finale is made prior to the decision on whether or not to renew the show being made, expect a finale that ties off most major plot threads, but leaves enough dangling to make it easy to carry on if the show is renewed.

If this is a two-season drama - even if the seasons are of irregular length - prepare to be burned.

'''Season Openers'''
* The first episode of Season 2 of ''Series/{{Supernatural}}'' showed pretty much everything going wrong. [[spoiler: Sam and Dean's father dies to save Dean's life and the Colt, which can be used to avenge their mother, disappears with him.]] This prompts Sam and Dean to gather what clues they have into finish what their father had been working on for over twenty years.
* On the television version of ''Series/OurMissBrooks'', the [[ExecutiveMeddling controversial]] fourth season began with the aptly named "Transition Show", in which Madison High School is torn down for a freeway, and Miss Brooks and Mr. Conklin find new work at Miss Nester's Private School.
* Horatio Caine's trip to Brazil in the Season 5 opener of ''Series/CSIMiami''.
* Buffy and the gang starting college in the Season 4 opener of ''Series/BuffyTheVampireSlayer''.

'''Lucky Episode 13'''\\\
For examples, see Front13Back9

'''The Ep-15 Shift'''
* "Phase One" of ''Series/{{Alias}}'' is a textbook example.
* The nuclear explosion in season two of ''Series/TwentyFour''.
* ''Anime/MaiHime'' ends the Searrs arc in episode 15 (in a YourPrincessIsInAnotherCastle moment), and episode 16 introduced a new and unexpected plot twist.
* "[[Recap/BuffyTheVampireSlayerS2E13Surprise Surprise]]" and "[[Recap/BuffyTheVampireSlayerS2E14Innocence Innocence]]" on Season 2 of ''Series/BuffyTheVampireSlayer''.
** Season 5 dropped the double whammy of "[[Recap/BuffyTheVampireSlayerS5E15IWasMadeToLoveYou I Was Made To Love You]]" and "[[Recap/BuffyTheVampireSlayerS5E16TheBody The Body]]" at this point.
* "[[Recap/BabylonFiveS02E09TheComingOfShadows The Coming of Shadows]]", a second season episode of ''Series/BabylonFive'', did this well enough to win a UsefulNotes/HugoAward. (It was actually episode 9, not 15.)
* Each of ''Series/{{Castle}}'''s three full seasons[[note]]It was a MidSeasonReplacement, so its first season is shorter[[/note]] has had a major two-parter with a big guest star representing a federal agency right about this time. They were:
** Season 2's "Tick, Tick, Tick..." & "Boom!", guest starring Dana Delaney, playing a specialist from the FBI.
** Season 3's "Setup" & "Countdown", guest starring Adrian Pasdar, playing a member of the Department of Homeland Security.
** Season 4's "Pandora" & "Linchpin", guest starring Jennifer Beals, playing a member of the CIA [[spoiler:& Soviet operative]].
* In ''Series/{{Supernatural}}'', episode 16 is usually pretty dramatic, and often a season game-changer:
** Season 1's "[[Recap/SupernaturalS01E16Shadow Shadow]]" has Meg being revealed as a villain and the brothers finally reuniting with John, albeit briefly.
** Season 3's "[[Recap/SupernaturalS03E16NoRestForTheWicked No Rest for the Wicked]]" was the season finale due to the writers strike, and includes Dean [[spoiler:being dragged into hell.]]
** Season 4's "[[Recap/SupernaturalS04E16OnTheHeadOfAPin On the Head of a Pin]]" has the first big sign that Castiel is good, the revelation that Dean broke the first seal, and the revelation that Uriel [[spoiler:is actively trying to help Lucifer rise; he is then killed.]]
** Season 5's "[[Recap/SupernaturalS05E16DarkSideOfTheMoon Dark Side of the Moon]]" has Dean and Sam in Heaven, and the revelation that [[spoiler:Castiel's plan to search for God really is fruitless.]]
** Season 6's "[[Recap/SupernaturalS06E16AndThenThereWasNone ...And Then There Were None]]" kills off no less than ''three'' recurring hunter characters.

'''Season Finale (Ep-20 to Ep-26)'''
* ''Series/DoctorWho'': "[[Recap/DoctorWhoS27E12BadWolf Bad Wolf]]"/"[[Recap/DoctorWhoS27E13ThePartingOfTheWays The Parting of the Ways]]", which ended with [[TheNthDoctor the regeneration of the Ninth Doctor]] into the Tenth Doctor and with Captain Jack Harkness being left behind on the space station for reasons the Doctor wouldn't explain until the Series ''3'' finale. (It should be mentioned that Doctor Who series only have 13-14 episodes per season, so this may not belong in this section.)
* ''Series/{{House}}'': Season 6 begins with [[spoiler: House's stay in the mental hospital, which mentions that he will be seeing his doctor for outpatient therapy after being discharged.]] This is not referenced again until a couple of episodes before the finale.
* ''Series/{{Terriers}}'' is a textbook example of a season finale that works as either a cliffhanger for next season or a satisfying resolution to the series. (It turned out to be the latter when the show was not renewed.)
* ''Series/TheHouseOfElliott'', a three-season PeriodDrama with ten episodes per series and no finite plot, more similar to an American series than the typical British literary adaptation or original period miniseries, ended on a cliffhanger with one of the sisters threatening to walk out on the eponymous fashion house. However, Creator/TheBBC then decided not to commission another series, so the series was left dangling.