You’re organizing a two-day theatre festival on a weekend at several locations. The locations vary in size. With a ticket you can go to all locations; meaning you can buy a passe-partout and day ticket and in both cases have access to all locations.
You are selling:
Passe-partout tickets.
Saturday tickets.
Sunday tickets.
You have four locations:
Main hall: 600 people.
Small hall: 300 people.
Foyer: 150 people.
Cafe: 100 people.
There are two options here:
An audience member buys or gets a (free) ticket / reserves tickets for a performance at a specific location, assuring their spot.
An audience member comes to the festival and decides on the spot which performance to attend, with the risk of the location having reached full capacity already.
For option 1, read more here.
For option 2, do the following:
Estimate the number of tickets you can sell each day. The capacities of the locations total a maximum of 1150 a day. You could add 100 for people who move between performances and, for example, go for a bite to eat. It's your festival, you know best how things will run, and how many tickets you can sell per day.
Use multi-access events for pass-partouts and day tickets. This is similar to option 1.
Exchange the tickets for festival wristbands, weekend wristbands or wristbands giving day access at the entrance.
During the event, the public walks around and chooses where they want to go. This means first come, first served. There is a place for everyone somewhere in the venue and as an organizer you will know how much audience a performance will attract and the best location to put it on.