Arnold Schwarzenegger was not too keen on playing the Terminator in the 1984 film “The Terminator”. He wanted to play Kyle Reese, the good guy. When asked about his casting as Terminator, he said “Oh some shit movie I’m doing” and its “Low profile” enough to not damage his career.

The Terminator

Casting Arnold Schwarzenegger as our Terminator, on the other hand, shouldn’t have worked. The guy is supposed to be an infiltration unit, and there’s no way you wouldn’t spot a Terminator in a crowd instantly if they all looked like Arnold. It made no sense whatsoever. But the beauty of movies is that they don’t have to be logical. They just have to have plausibility. If there’s a visceral, cinematic thing happening that the audience likes, they don’t care if it goes against what’s likely.

—James Cameron on casting Schwarzenegger.

For the role of Kyle Reese, Orion wanted a star whose popularity was rising in the United States but who also would have foreign appeal. Orion co-founder Mike Medavoy had met Arnold Schwarzenegger an… Continue Reading

Source: https://en.wikipedia.org/wiki/The_Terminator#Pre-production