Qualifications
The qualifications to enter Delta Force are very strict. Remember when we said that they primarily recruit from other Special Forces Units? Well, take whatever those already elite guys require and double it.
All applicants must be male. (The females of the "funny platoon" are actively searched for rather than applying). They must be between at least twenty-one years old, have served two years within another Special Forces Unit, and score incredibly high on the Armed Forces Vocational Aptitude Battery tests...just to get their foot in the door (source).
Next is the physical test, sort of a "Rocky" montage minus the music. Push-ups, sit-ups, a two-mile run, an inverted crawl, and a 100-meter swim fully dressed. This is followed by a series of land navigation courses, including an eighteen-mile all-night land navigation course while carrying a ninety-pound rucksack. The physical testing ends with a forty-mile march with a forty-five-pound rucksack over very rough terrain. Oh, and did we mention that there's no food and no sleep allowed? Right....
Okay, so you made it through the physical test...somehow. Now comes the mental portion. Recruits are placed in front of a board of Delta instructors, unit psychologists, and the Delta commander, who each ask the candidate a barrage of questions. They then dissect every response and mannerism of the candidate with the purpose to mentally exhaust the recruit. If you blink at the wrong time, you could be out.
If an individual passes all of these tests, he undergoes an intense six-month Operator Training Course (OTC), to learn counter-terrorism and counter-intelligence techniques, including firearm accuracy and various other munitions training. He is again tested after the training. Then, and only then, can he join the Unit.
But he still joins as a non-operational member until he has proved himself. We know, we know. Life just ain't fair.