sctatched records

Well, since I can't say it will help, I guess I have to say it could damage the stylus tip. Depends whats in the groves, but if they are truly dirty the answer is definately yes. Clean your records before you play them - the clicks and pops from scratches and production defects will not really do any damage.

I got a few old records from a friend and one of them had several deep scratches and I was afraid to even try and play it.

Agree that a dirty LP can lead to excessive wear on the needle, in turn the worn needle will ruin your LPs.
Clean LPs even with scratches will not damage the needle.
IF the nick or mark is deep and causes the needle to jump out of the groove... THAT LP or at least that section should not be played. The needle tip is GLUED to the mount, and could be knocked off with a hard enough hit.
But the playing of cleaned scratched LPs should cause no harm.

Elizabeth is dead on, as usual. All I can add is that scratches are louder and more dangerous if the 'needle' is not correctly placed. If it is off the vertical axis, any collision will be at a more acute angle. I have had my clean records scratches get quieter with several plays ad the stylus shaves off the anomolies. Finally, use Last preservative after cleaning. It makes it quieter and more smooth.