If you want to unlock Palpatine the long way, then you have to get every system under Republic control. If you want to use the cheat code, enter 5C62YQ.
To get the emperor in LEGO Star Wars III, get all the minikits in the Geonosis Arena (aka the prologue). Once you do that, take the elevator in the medical center on the Republic starship, star-destroyer hubworld. You will see tanks with characters floating in them. To get the empreror, go to the tank with the emperor, and press "release". This will release the emperor, and you will be able to buy him. The emperor (or Darth Sidious, as he is called in the game) will cost 275,000 studs (the currency in the Lego Video Games).
Code= darkside
You have to get all the systems under Republic control.
palpatine
Chewbacker isn't in the Lego Star Wars 3 beta.
It was widely assumed that Palpatine's master was Darth Plagueis.
Unlike in the first LEGO Star Wars game, Emperor Palpatine/Darth Sidious is able to use Force lightning along with wielding a lightsaber.
Code= darkside
His name was Palpatine.
You have to get all the systems under Republic control.
palpatine
Chancellor Palpatine/ The Emperor
You have to beat Jedi Destiny to unlock the emperor in P.C.
you get emeror palpatine
5c62yq
Mainly Emperor Palpatine
Emperor Palpatine
The Emperor is Star Wars was called Palpatine. He was played in the movies by British actor Ian McDiarmid (Except the original version of The Empire Strikes Back in which he was played by Clive Revill)