Scratched movie software vs. music CDs

We all know that if we scratch a surface of CD most-likely it will play fine.
What if we scratch LD or DVD?
I've already had a bad experience receiving scratched LD bought on ebay and on the side where the scratch is I have locally shaded picture.
Is it because of the scratch?
From my experience a scratched laserdisc will behave the same as a CD for sound (clicking sound, skips, etc, or if worse it locks up) and the same as a damaged or creased video tape for the picture (moving white lines, jumping picture from skipping, etc.)

If you told us you have tiny white dots all over the screen it would probably be laser rot which afflicted some early laserdiscs when they got old.

...just the way you've described Sugar.. I've all of that: white dots, lines of a different colours running through the screen on one of the 4 parts of 4 Rooms movie.
How old is this Laserdisc. I've seen laser rot usually in the pre-digital "CX" coded laserdiscs, but that does not mean it is not that.
If you want first hand experience with scratched DVDs, get a membership to Netflix - almost every DVD they send me is scratched up something fierce. Almost all of them play flawlessly, so I think they can be pretty abused and still work fine. -Kirk