Conveyor-Belt Missions are a type of mission. Instead of towers being bought with money, they come from a conveyor on the bottom of the screen, above the special agents bar. These towers cannot be upgraded. The agents can be Pro or Epic, but won't always. Some (and most) of these levels also feature pre-upgraded towers. The conveyor can create a tower/agent every 3-15 seconds. Each tower/agent may be Common, Uncommon, Rare, Very Rare, and Epicly Rare. Common towers/agents appear 50% of the time, Uncommon ones appear 30% of the time, Rare ones appear 15% of the time, Very Rare ones appear 4% of the time, and Epicly Rare ones appear 1% of the time.