A barbarian with at least 13 in one prime requisite gains a 5% bonus to experience. If both STR & CON are 16 or higher & the barbarian gets a +10% bonus.
A half-elf with at least 13 INT & STR gains a 5% bonus to ex-perience. A half-elf with a score of 16 or higher in one prime requisite & a 13 or higher in the other gains a 10% bonus.
A halfling with at least 13 in one prime requisite gains a 5% bonus to experience. If both DEX & STR are 13 or higher & the halfling gets a +10% bonus.