Final answer:
Macbeth is the protagonist and King Duncan is the antagonist in Macbeth Act 1 Scene 1-4. There is no clear hero who saves the day, but Macbeth himself is the bad guy who must be defeated.
Step-by-step explanation:
The protagonist in Macbeth Act 1 Scene 1-4 is Macbeth himself. He is a noble and brave soldier who later becomes consumed by ambition and commits terrible deeds. The antagonist in this part of the play is King Duncan, who is Macbeth's ultimate target. Duncan is portrayed as a good and virtuous king.
In terms of the good guy who saves the day, there isn't a clear hero in Macbeth. The play is a tragedy, and the actions of the characters ultimately lead to their downfall.
The bad guy who must be defeated would be Macbeth himself. His ambition and hunger for power lead him to commit murder and betrayal, ultimately causing his own downfall.