No inherent effect. Many Ritualistskills, especially those related to healing, life stealing and defense, become more effective with higher Restoration Magic.
Restoration Magic is the primary source of a ritualist's ability to heal teammates. Similar to monks' Healing Prayers, Restoration magic has several important differences that must be taken into consideration in order to be used effectively.
Restoration healing is noticeably more efficient than Healing Prayers, in terms of energy spent per life gained. This is to compensate for the ritualist's lack of Divine Favor. However, because Restoration Magic is not directly influenced by a primary attribute, it is much more accessible to secondary ritualists.
Many Restoration skills are situational, meaning that they require a spirit, weapon spell, or item spell in order to perform optimally. Synergy is key in using Restoration skills effectively.
In addition to raw healing, Restoration magic offers several support skills in the form of blind infliction and life stealing.