Just as the title of the game suggests, you play a smuggler. A smuggler who is carrying either illegal weapons or contraband drugs or a few other kinds of material. Since you have these illegal things in your possession, you are a prime target. A target by law enforcement, a target by rival smugglers and gang, a target by more militaristic forces of the United States.
If you can survive the high speed chases, the off-road evasion, the gunfire and the dust... you stand to make quite a profit. Maybe enough to outfit your vehicle for your next smuggling endeavor. Something that will make the next run a little less hazardous.
Altogether there are over 30 missions inside of 3 distinct and vast environments. Vast in the full sense of the word, in that you can drive literally anywhere with the game's areas... and get lost doing it too. This style of gameplay is a staple of the Smuggler's Run series and Grand Theft Auto 3 or Vice City