From publisher blurb: The alchemists at Creation's Edge Games have whipped up 50 new potions for your d20 fantasy campaigns. Sample: Selective Non-detection (animals) This potion makes the imbiber undetectable to animals. Creatures of this type cannot perceive the user of the potion as they normally would. If the animal has reason to believe that an undetectable creature is present they can still attempt to attack them suffering all the applicable penalties for attempting to attack an 'invisible' target. If the undetectable creature takes action against an animal, such as physically attacking or casting a spell at, the potion's effect becomes temporarily disrupted, making the creature fully detectible by the animal the following round. If the creature takes no action against the animal for the round that they are visible to it the potion will kick in once again the round after that rendering the creature effectively 'invisible' once again. The effects of this potion last for 1d4 hours.