The Chant spell affects attack rolls, damage rolls and saving throws of all creatures in its area of effect. All allies receive a +1 bonus those while enemies receive a -1 penalty.
Note: Spell descriptions shown in-game often differ significantly from their actual in-game implementations.
By means of the Chant spell, the priest brings special favor upon him- or herself and his/her party, and causes harm to his/her enemies. When the Chant spell is completed, all attack and damage rolls and Saving Throws made by those in the area of effect who are friendly to the priest gain a +1 bonus, while those of the priest's enemies suffer a -1 penalty. Multiple Chants are not cumulative.