Antidragon Aura(Draconomicon, p. 109)
Level: Cleric 4, Sorcerer 4, Wizard 4, Spellthief 4,
Components: V, S, M, DF,
Casting Time: 1 standard action
Range: Close (25 ft. + 5 ft./2 levels)
Target: 1 creature/two levels, no two of which can be more than 30 ft. apart
Duration: 1 minute/level
Saving Throw: Will negates (harmless)
Spell Resistance: Yes (harmless)
All targets gain a +2 luck bonus to Armor Class and on saving throws against the attacks, spells, and special attacks (extraordinary, supernatural, and spell-like) of dragons. This bonus increases by +1 for every four caster levels above 7th (to +3 at 11th, +4 at 15th, and a maximum of +5 at 19th).
Material Component: A chunk of platinum worth at least 25 gp (slightly less than 1 ounce).