Theme park attractions are notorious for their unpredictability. If you’ve spent any significant amount of time in a major theme park, you’re well aware of how often rides go down. If you’re at Disney, the official terminology for an attraction that’s not operating is “101.” When the ride is operational again, it’s deemed “102.” If you want to feel particularly theme park savvy on your next visit and you’re wondering whether an attraction is working, just ask the nearest Cast Member if it’s 101 and you’ll get your answer.

You probably won’t get a conclusive answer about what’s going on when an attraction is 101 no matter what fancy phrases you use. However, there are a few common issues that are nearly always behind an attraction down time. If your favorite attraction isn’t running when you visit, it probably comes down to one of these causes.

1. System failures

System failures are pretty ambiguous, and even many attraction Cast Members are unaware of the specifics behind a failure on any given ride. There are numerous faults that can trip on an attraction. Depending on the specifics of the error, the ride may stop temporarily or it may perform an emergency stop (e-stop).

Every ride has its own operating procedures for the specific stops and faults that can occur, so there’s no blanket rule for how a particular problem is handled. If it’s a minor issue, the Cast Member in the tower may call the greeter and ask him to her stop letting new guests into the queue, yet continue to cycle out the ride. This means that guests who are already in the line will still get to ride, and the issue is obviously a minor one that’s related to show rather than safety.

If there’s a more serious issue, Cast Members may need to turn guests away. The Tower will instruct the appropriate Cast Members to dump the queue, meaning that guests already in line will be sent away. Those who have made it past a certain point in the line may receive a ticket for reentry later in the day. In some instances, the entire ride may have to be evacuated. In this case, Cast Members will turn on the building lights, walk out onto the track and retrieve guests already on the attraction, guiding them to the appropriate exit points.

In any of the above scenarios, guests who are outside the attraction will be turned away and told that the ride isn’t currently operational.

2. Guests misbehaving

Safety is the top concern for every Cast Member at Disney. While they want you to have a magical time sprinkled with pixie dust, all the charm comes to a halt when it’s a matter of preventing an injury. There are ample warnings and instructions for every attraction telling you how to behave properly and enjoy the experience, but some guests still ignore these admonishments, and often ruin the fun for everyone in the process.

If a guest stands up, reaches outside their ride vehicle, or otherwise disrupts the ride experience, Cast Members may have to stop the attraction, slowing down operation and increasing wait times for those outside the ride. Depending on the severity of the offense, this might involve hitting an e-stop. Every attraction is different, but many rides require an extensive reset after hitting an e-stop, which may involve evacuating the attraction and shutting down the entire ride for a period of time.