Are you confused when you read a guidebook climb description of “5.10c R M8 WI5+ Grade IV?” Yeah, me too.

For a refreshing simplification, have a look at Yosemite pioneer Jim Bridwell’s Casual Rating System, which describes any climb in just four categories.

• NBD = No Big Deal

• NTB = Not Too Bad

• PDH = Pretty Darn Hard

• DFU = Don’t F**k Up