According to the Skull & Bones rulebook, clerics are not suitable for use as Player Characters because they have lost the ability to cast divine spells unless they possess a holy relic. While this helps to create a gritty, low-fantasy feel for a historical pirate campaign, it also prohibits what can be a fun type of character to play. For example, a Robin Hood type preacher who sails with pirates but tries to do right by the Lord could provide many chances for good roleplaying.
To facilitate these kinds of opportunities, this article presents a variation in which clerics can cast spells, but only ones that do not have perceivable effects. This gives them a subtle influence over the world around them, but reflects the fact that they no longer wield the power that was once common.
Refer to the following list for spells that are still permitted.
Level 0—Guidance, Resistance, Virtue
Level 1—Bane, Bless, Divine Favor, Doom, Entropic Shield, Magic Weapon, Protection from Chaos/Evil/Good/Law, Shield of Faith
Level 2—Aid, Align Weapon, Bear's Endurance, Bull's Strength, Consecrate, Desecrate, Eagle's Splendor, Owl's Wisdom
Level 3—Bestow Curse, Dispel Magic, Magic Circle Against Chaos/Evil/Good/Law, Magic Vestment, Remove Curse
Level 4—Death Ward, Divine Power, Greater Magic Weapon, Spell Immunity
Level 5—Atonement, Dispel Chaos/Evil/Good/Law, Hallow, Spell Resistance, Unhallow
Note that, because there are so few appropriate spells beyond 5th level, it is recommended that the cleric class caps at 10th level.
The D20 SRD presents many different domains to represent a diverse pantheon of deities. Among these, only a few (Good, Law, Protection) are appropriate for representing the major established faiths of a historical game. Others could be used to represent non-European or Middle Eastern traditions, such as a Mayan priestess.