Rules are one of the areas where it's easy to all mixed up--especially when you use more than one at the same time. They're also one of the tools most easy to miss in the Back Office. Rules can be super powerful, especially in combination with memberships, ticket packages, and private allocations.
We've been doing a lot of work on how rules function and making them easier to manage. Ticket rules, in particular.
On the details page for each showtime, for instance, you'll now see which rule is truly limiting each customer to a max quantity of tickets.
For example, if you have a special, limited ticket, you can set the default ticket max per customer on that ticket to 10 per showtime.

On specific showtimes, you can lower the max number of tickets users can get. Visit any showtime and go to the bottom of the page, where you see when tickets go on and off sale. Change the ticket view to rules.

Here you can clearly see what the default rule is and lower it just for this showtime. The blue highlight will show you which rule is the winner--whichever is the most restrictive.

Also, don't miss the bulk rules tools in the Tools menu.

The power user's guide to ticket rules can be found here.
