A Quake unit is about 1/32 meter (20% longer than an inch, although many people mistakenly believe Quake units are inches) and the network protocol allows for 1/8 Quake unit or 1/256 meter precision (less than 0.5 cm) with 16 bit coordinates, so the playable area is 216/256 or 256 meters wide. (If the protocol were changed to 1/2 units, the precision would be 1/64 meter (less than an inch) and the playable area would be more than a kilometer wide)