So, tobacco kills but it's legal
which goes to show you how meaningless drug clasifications are, and what they say, huh?
Think about what LSD does, how it makes you feel. And then ask yourself how it does it. Then ask yourself if it can do all that, how it could do it harmlessly. How could it create those effect and have no other effects, too.
There's a reason it's called 'Acid' (not just it's nick, either).
Spend some time Googling, and see what you find.