Cooperative Magic (TOM)

Cooperative spells are unique to priests. These spells allow several priests to combine their abilities to create a greater effect. Combine is one type of cooperative spell.
Cooperative spells do not require a focus or devotional energy; all that is required are two or more clerics of sufficient level to cast any cooperative spell. Casting times for cooperative spells are not excessive and their results are spectacular, making cooperative magic practical and useful to adventuring priests.
All priests who attempt cooperative magic must know the spell to be cast and must be of the same ethos. Generally, only priests of the same religion can use cooperative magic. However, priests of deities known to work in close harmony are sometimes able to use cooperative magic with each other. The decision lies with the DM, since the relations between different deities vary greatly from campaign to campaign.