what is esc

[nitrost]

It said rustler rtr w/esc i dont know what it means

 

[fisherman]

Electric Speed Control, no offence know your a noob but i run nitro and i know that its ok i wouldnt have known it unless i joined here, you learn tons on this site.

hope you enjoy your electric

 

[Rolex]

Actually, Electronic Speed Control. It replaces a 'sweep' type that needed a servo to sweep the contact over 3 different contact points, which in turn went through a ceramic resistor to give you 3 preset speeds.
The ESC does not need a servo.