No. But if there are events they charge you to enter depending on what events Sean, when I visited The events were free (Jr. NBA Global championship)
ESPN is only open to the public when there is an event. It is not a normal "attraction" for most who come to Disney World since there are no rides. Multiple events can happen at the same time as the facility is huge. ESPN just "hosts" the event and does not control pricing. ESPN provides support services for the event. It's up to the event sponsors as to the price of the ticket for their event. If there are multiple events at the same time they don't normally stop you at the main gate but at the entrance to the building / field that the event is being held in to check your ticket. So in short unless you know of an event happening there you want to attend there is not much other reason to go.
When I went there were events and I paid for admission, when there aren't I don't know how it works.
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