In the game, if you do things 4 times correctly, you should win. (i think)
If you're stuck:
- Crazy caller is either unsure or just talks nonsense. Ignore him. To do so, select valve and pick 3rd option.
- Terrorist says only the opposite of what to do. Ask him what to NOT do and do that.
- Sapper says only useful information.
To distinguish them, follow this:
- If caller is unsure, its crazy one. starts with (I think I know)
- Ask what not to do.
- If some unrelated stuff is told, its crazy one. like (acoustics, sneeze and don't look)
- If caller starts with "DONT do something" when asked what not to do, then its a sapper. Trust him.
- Else it's likely a terrorist. Follow his DONTs.
It's about 80% correct strategy. You'll win eventually.