Milestones (Power Rangers)

As a franchise, Power Rangers is constantly evolving and changing, with new ideas and concepts emerging with each series, both stemming from the original source, Super Sentai and as written into the adapted show. This is a real-world documentation of the evolution and the milestones in the franchise, showing the changes, advancements and quirks which emerge with each new series since originally starting in 1993.

Season One

 * First to be adapted from Super Sentai
 * Established a five-man team with a Sixth Ranger
 * Established the use of morphers.
 * Established the use of sidearms.
 * Established the use of combining weapons.
 * Established the use of Zords.
 * First to switch a Ranger's genders from the original source.

Season Two

 * First to have a second Megazord combination for a team.
 * Only adaptation to not use the adapted season's core rangers' suits.
 * First villain exclusive to Power Rangers.
 * 100th Power Rangers episode (not counting non-sequential specials): Rangers Back in Time, Part II

Season Three

 * First to have a third and fourth Megazord for a single team.
 * First Rangers with Ninja-based powers
 * First to feature a Monster-of-the-week non-affiliated with the main villains.
 * First series to feature a Non-Power Ranger hero, as well as crossing over with another Saban show.

Alien Rangers (Mini-Series)

 * First to have non-combining zords.
 * First team to be led by a female, with Red taking point as figurehead.
 * First to have a [[Tideus|male Yellow Ranger.
 * First to feature another Ranger team.

Zeo

 * First full-on change of powers, suits and arsenal for the titular Rangers.
 * First new villains.
 * First series to have a team up with the previous team.
 * First series to use footage from Super Sentai crossover movie.
 * 200th Power Rangers episode: A Mystery to Me

Turbo

 * First to premiere with a full-length movie.
 * First series with carrier zord that doesn't combine with megazords.
 * First series with carrier zord that also transports zords into battle.
 * First series with car themed zords.
 * First series with zords with both a vehicle & humanoid mode.
 * Only series with a child as a ranger.
 * First series with a female mentor.
 * First series with a new mentor & assistant.
 * 5th anniversary of Power Rangers
 * Final series to include Tommy Oliver as a ranger before acquiring a new color seven years later.

In Space

 * First series to have a 2 piece Megazord.
 * First series to have a 3 piece Megazord.
 * First series to keep the original sentai robo names for Megazords.
 * Final series to feature Zordon.

Lost Galaxy

 * First series to not directly follow on from the last.
 * First series to introduce a new cast with the first episode (except, obviously, Mighty Morphin).
 * First villains without any connections with the United Alliance of Evil.
 * First Ranger to die.
 * First former villain to become a Ranger.
 * 300th Power Rangers episode: Double Duty

Lightspeed Rescue

 * First series to feature an American-exclusive ranger.
 * First series to not feature any elements from past series (outside of the team-up).
 * The team up in this series is the first to be self-contained whereas the previous two had effect on the storylines.
 * First series not to feature an Alpha robot.
 * First non-alien villains (demons).

Time Force

 * The first time the monsters don't get destroyed.
 * 400th Power Rangers episode: Lovestruck Rangers

Wild Force

 * First series to have a team-up featuring a team from various other teams.
 * Last to switch a Ranger's gender from the original source.
 * 10th anniversary of Power Rangers

Ninja Storm

 * First to have brothers that are Rangers.
 * First to include a female Blue Ranger.
 * First to begin with a three-member team.
 * First series to be filmed in New Zealand.

Dino Thunder

 * Only series with four Rangers on the core team.
 * First series to use its corresponding Sentai season unmorphed footage for an episode.
 * 500th Power Rangers episode: Legacy of Power

S.P.D.

 * First series not to take place in the year it aired.
 * First series with an evil ranger team that willingly became evil/is corrupt.

Mystic Force

 * First ranger team to have a magic theme.
 * First ranger team with a ranger with parents who are also rangers.
 * First ranger team that transforms into their zords.
 * First to have sisters that are Rangers.
 * 600th Power Rangers episode: Light Source, Part I

Operation Overdrive

 * Season introduces 3 growing methods
 * 15th anniversary of Power Rangers

Jungle Fury

 * First purple ranger joins the team.
 * First Black/Green ranger-like ally duo.
 * First ranger-like duo to start out evil then later turned good.
 * First extra heroes whose zords can combine with those of Rangers'.

RPM

 * First 6th Ranger duo.
 * First regular core team to include both a Green and Black, if the Retro Rangers line up isn't counted.
 * 700th Power Rangers episode: Danger and Destiny, Part II (also the season finale)

Samurai

 * First heroic team to have a female Red Ranger.
 * First ranger team with a Samurai theme.
 * First series to use footage from a non-cross-over Super Sentai movie.
 * First series produced by Saban since being sold to Disney.
 * First Saban season filmed in New Zealand
 * First Sentai adaptation to be split into two years.

Megaforce

 * First series to use footage from two previous unadapted Super Sentai series in a single episode.
 * First anniversary series where the celebration was split into two halves because of Nickelodeon's distribution agreement with SCG and Toei.
 * Fan Celebrations for the milestone went on since last year.
 * First 6th ranger to be played by a production staff member for the show, (2nd unit assistant director Chris Auer, who worked in the same capacity for 5 prior series to this one).

Dino Charge

 * First series to skip over its corresponding Sentai season's predecessor.
 * First series to have one female on the five-man team (that isn't the leader).
 * 800th Power Rangers episode (counting Halloween and Christmas specials since Samurai): True Black.
 * First season to not have a Yellow Ranger.

Ninja Steel

 * First series to have a White Ranger and Pink Ranger on the same team.