A Conditional Instant Prize is a special system where, even if instant prize symbols (like coins) appear on the screen, the prize is not paid out on its own. A reward is only paid if a separate, specific 'Collect' symbol appears at the same time.
The core of this feature is to add a new goal and tension to the base game by imposing a 'condition' that two elements—the 'instant prize symbol (the lock)' and the 'collect symbol (the key)'—must appear within a single spin.