For a starting character (not a henchman), the minimum expectation is that one of these stats will equal at least 17, OR, one of these stats will equal 16 and one will equal 15. My experience has been that while many characters are prepared to run characters with lower stats, this becomes a problem after a player has run that character for eighteen months or more. Since the majority of my players will continue to play a given character in my world continuously, most often for years, I insist that their first character be at least marginally special.
The six final numbers are then arranged at the player desires into the various six stats:
Strength ~ physical musculature and power
Intelligence ~ problem solving ability and alertness
Wisdom ~ education and willingness to learn from mistakes
Constitution ~ sturdiness and overall health
Dexterity ~ agility and reflex
Charisma ~ physical attractiveness, persuasiveness and personal magnetism
Based on the minimum requirements in the AD&D Player's Handbook, the player selects the character class and the character race. See character race limits. The player also selects the character's gender.
While many things are forced upon the player as a result of the background generator I employ under the argument that one does not choose one's place of birth, family, originating wealth and so on, I am prepared to wave this where it comes to gender, because I believe most players are deeply opposed or desirous of playing given gender roles.
Once the player provides their six stats (modified by racial adjustments, but NOT by age), their gender, class and race, I then generate the player's background using my character background generator.