This was for a game in which the PCs were fighting the rule of an evil band of knights. Affiliation rules were found in the PHB II (3e).
Criterion / Affiliation Score Modifier
Character level +1/2 PC's level
BAB +6 or higher +1
Helping kill a black knight +2
Killing a dangerous monster +1
Knight Class +1
Refuse a request for rescue -3
Intimidating the populace -1
3 or lower Nobody: No affiliation or junior member with no benefits.
4 - 10 Adventurer: A mayor or other personage presents you with a masterwork lance or other melee weapon. You have a -4 to defensive social checks against members of the peasantry.
11 - 17 Hero: A grateful commoner will present himself as your henchman so long as you do not have more henchmen than CHA MOD. If this henchman should perish, a new one will pledge himself next time you enter an appropriate town.
18 - 22: Champion: You gain the toughness feat. You must defeat an enemy of the populace each week or you will suffer a -4 to your affiliation.
23 - 29: Idol: You enjoy a +1 inherent bonus to an ability score of your choice. You cannot use non-masterwork/non-magic weapons or armor, or you suffer -1 affiliation per day of usage.
30 or higher Legend: Any henchmen, familiars, or mounts you have enjoy the toughness feat. You enjoy a second +1 inherent bonus to an ability score of your choice.