Hidden Characters
SPOILER---DON'T READ UNLESS YOU ARE STUMPED ON HOW TO FIND THESE CHARACTERS!!!
How to get Yuffie--
I suggest getting her after you battle at Condor Fort on Disc 1. To do this, get into battles in the forest areas (some are near Condor Fort). After about 8 to 12 battles, you will fight Yuffie. After beating her, you pop up in the forest. DO NOT use the save point, instead talk to Yuffie, answer her questions in this order :Second Choice, First Choice, Second Choice, First Choice, Second Choice. if you answer the questions wrong and she will run away. and maybe steal some of your gil.
How to Get Vincent--
When you go to Nimbelheim , go to the Shinra Mansion and read the note to left of the first room. Pay attention to the clues to get a key item from the safe upstairs. (The Combo is Right 36, Left 10, Right 59, Right 97). After opening the safe, you will have a difficult fight with Lost Number. You will also get 'Basement Key' which will get Vincent in your party...he is downstairs in the basement, in the coffin.