What did Zack contribute to the original FF7?

[Nod]

Zack was a convenient story-telling tool to add depth to the game; a character that had an apparent profound influence yet we never actually get to find out much about him

[Christmas]

I think the fact that he saved Cloud and enable FF VII to happens kinda contribute a lot!

[Kenshin IV]

Do you mean what did he contribute IN the original game, or do you mean how did his Crisis Core character contribute to the events in the original?

Because in the original he was a very minor character, and mostly served as being the main "twist" -- Cloud believing he was actually Zack.

As for Crisis Core, that game was really its own story. The only connections the developers made with Final Fantasy VII were forced. Otherwise, it really was mainly about Zack and his relationships with Angeal and Gac-er, Genesis.

[Shaibana]

like many other ppl say: Cc does explain some thing in FF7, but its also a story on his own.

Without Zack there wouldnt be a FF7.. becaus Zack sort of shaped Cloud to what he is now... not just becaus theyre minds are mixed up, but also becaus Zack was a sort of mentor to Cloud.

So yes, i do think the events of Crisis Core are (somewhat) important for FF7