mctrivia: You misunderstood. There are 2 types of conditional moves:

1."If my opp plays x then I play y. This may be useful, but how often can you predict the opponents move?

2.Propose to your opponent the next few moves. If he or she agrees play continues from that point. This is very useful in many "semi-forced" continuations. Against a weak opponent you may be hoping for a silly error, but a good player is likely to see the same continuation and agree.

example.
After
1.e4 e5 2.Nf3 Nc6 3.Bb5, black could move 3...a6 with the proposal 4.Ba4 Nf6

If white accepts he can play move 5 immediately. If not he may play an alternative to 4.Ba4.