In every Sentai series, the fight between good and evil is illustrated, with the good side winning most of the time. The basic premise of the series is that a group of five (in some cases fewer) people gain special powers (magical or technological), wear colored outfits, and use advanced weapons and martial arts skills to battle powerful beings from other planets and/or dimensions threatening to take over the Earth. In most of the episodes, after the team has beaten an army of evil creatures ("grunts") and the "monster of the week", they call for huge robotic vehicles/animals ("mechas") that can combine to form one giant robot to fight an enlarged version of the monster. Sentai series with the giant robot element are specifically known as Super Sentai. While each Sentai series is set in its own reality, a number of TV and video specials feature a teaming up with previous Sentai.