Continuity mistake: When the Villains send their cronies (for example, Putties, Tengu Warriors, Cogs, Piranhatrons, etc.), their numbers constantly change from when they arrive, to when they leave. This is due to the use of Japanese footage used from Kyoryu Sentai Zyuranger.
Continuity mistake: When the Rangers morph, the clothes they are wearing don't match what they have been wearing that episode - this also applies to hair.
Continuity mistake: In the 12 series (Power Rangers Dino Thunder), in the episode "White Thunder Part 3", The Red Ranger throws his blaster to the ground whilst fighting the White Ranger. In the wide shot, the blaster disappears.
Continuity mistake: Whenever we see the Rangers morph it is always the same clip that is used to show this. This is especially apparent towards the middle of Season 2 when Zack has dreadlocks in the program, but his crew cut hair in the morph sequence. (00:07:25)
Answer: According to the IMDB, there are currently 10 different series (with an 11th premiering in 2006). And, as far as I can tell, there have been only two theatrically released movies. All of the series, with the exception of the first one (that premiered back in '93) are spin-offs of the original, and they all share similar plot lines, characters, etc.
Cubs Fan ★