When the ultimate betrayal comes to surface, 8 friends will become enemies and only 1 will be left standing.

8 friends will become enemies with the betrayer or each other? It's just mush.

"Ultimate betrayal " is vague.? What does that mean?

And the logline also contains a spoiler; it gives away the ending (only 1 will survive). That is something a logline should never do.

Hi Kathryn,

As variable said earlier, this is a tagline for a movie, not a logline.

As a logline it's incredibly vague. You could describe a crime thriller in vein of Reservoir dogs or a high school comedy where 8 friends are vying for the same guy for example.

Until we get more details, it will be difficult to help you develop the concept or improve on the logline.

If the betrayal is a big reveal at the end of the movie, then it is true, you should not reveal?it in the logline.

However,?we still need a specific event in the logline that sets the story in motion.

Thanks for the feedback. If I tell you what it is then it spoils the plot of the movie. I tell you enough to peak your curiosity which proves my point.

Some questions pop to mind -
1. Who betrays whom?
2. Who's your protagonist?
3. What was the nature of betrayal? &
4. ..As a result of which, what becomes the protagonist's GOAL

PS. If you are aiming to write for multiple protagonist's, the link below might be helpful:
https://loglines.org/logline/how-to-write-a-story-with-multiple-protagonists/

Good Luck!!