A phantasia character's abilities are determined by his/her statictics. These attributes change as a player ages or goes up in levels and can be enhanced with equipment found as treasure or bought at trading posts.
Here's a list of Phantasia's basic character statistics.
strength - determines how much damage a character will inflict with melee or skirmish.
quickness - a higher quickness gives you better chance of winning initiative in combat. Quickness can drop when too much gold is carried or when the character gets tired from too much fighting without rest.
energy level - specifies how much damage a character may endure before dying.
magic level - determines which spells a character may throw, and how effective those spells will be.
brains - basically, the character's intelligence; used to calculate the sucess of luckout.
experience - experience is directly connected to levels. It is gained by fighting monsters and other characters.
level - a general rating of a character. Each time a character goes up a level, most other stats are improved.
poison - sickness which degrades a character's performance (affects energy level and strength).
sin - accumulated as a character does certain nasty things. Players with high sin tend to be shunned by helpful creatures.
age of player - roughly equivalent to number of turns. As age increases, many personal statistics degenerate.