Does Curse really cause this effect?

Question

My friend said that once a pokemon used Curse on his pokemon,and from then on his pokemon always used an unexpected move(he didn't pick the move).
I was wondering,was he lying or do pokemon in his version,Heart Gold,that have had Curse used against them really have that happen to them?

Comments

That makes no sense.

Answer 1

Curse is a move that has a different affect for ghost pokemon and non-ghost pokemon

Ghost types:the user cuts his/her hp in half and constant damage is dealt to the opponent

Non-ghost types: The user lowers its speed but raises its attack and defense.

If neither of these describes what happened to your friend then he is lying