You can create a group discount by adding a ticket type. If you have already created an event, follow these steps.
First click the Details tab on the Event Home and then click Add A Ticket.
After clicking Add A Ticket, you can edit the group ticket type information in a new window.
Name: name your Group ticket type. I named it "Group"
More Info: enter a description of the ticket type. I included info on the group discount
Pricing: set your ticket price at Paid.
Price: enter the discounted dollar amount for your ticket. My group discount price is $8.50 per event goer
More Options: limit sales dates, limit inventory (the amount of tickets you want to sell) and restrict the number of tickets that a patron can purchase per order. Set the Minimum at the number of tickets a group discount becomes available. In my case 10 = a group.
Report Grouping: This optional field can be used for any purpose you desire.
Barcode Ticket Options: if you enable barcode tickets, patrons will receive their purchased tickets in an email.