Celebrate pi, pie, and all things circular at Rager Pie on March 14 (aka 3.14). They will have pie-related games and challenges available all day, with prizes to be won including pies, alcohol, and vouchers. 

If you don't manage to make it to Rager Pie during the day, you can also try out their mysterious challenge at 8-Bit, Capital Spirits, or Bar 49 in the evening.