An Ioun stone is named after Ioun, a god of knowledge and prophecy revered on some worlds. Many types of Ioun stone exist, each type a distinct combination of shape and color.
When you use an action to toss one of these stones into the air, the stone orbits your head at a distance of 1d3 feet and confers a benefit to you. Thereafter, another creature must use an action to grasp or net the stone to separate it from you, either by making a successful attack roll against AC 24 or a successful DC 24 Dexterity (Acrobatics) check. You can use an action to seize and stow the stone, ending its effect.
A stone has AC 24, 10 hit points, and resistance to all damage. It is considered to be an object that is being worn while it orbits your head.
- Capacitance (Rare): While this sparking cyan rhomboid circles your head, it absorbs the first 5 points of fire or electric damage that would have been dealt to you each turn and deals it back to the attacker if they are in the same spot the next turn. If you are subject to more than 15 points of fire or lightning damage in a single round the stone burns out and falls to the ground and the damage is dealt to you instead.
- Dark Sight (Very Rare): You gain Darkvision to 60 feet while this dusty obsidian chunk floats around your head. Your Darkvision extends to 120 feet if you already have it.
- Leaping (Uncommon): While this indigo ellipsoid orbits your head, your jump distance is doubled. You can also make running jumps with a a 5-foot run instead of 10.
- Load Bearing (Uncommon): Treat your carrying capacity as if your Strength score were 4 points higher while this flawed crystal ellipsoid orbits your head.
- Luck (Very Rare): You gain one use of the Lucky feat while this emerald rhomboid orbits your head. This stone recharges after you take a long rest.
- Immortality (Legendary): You never age while this heavenly white sphere orbits your head.
- Initiative (Rare): Your Initiative score increases by 2 while this marbled blue and white rhomboid circles your head.
- Speed (Very Rare): Your based movement Speed increases by 5 feet while this lime green spindle zips around your head.
- Tongues (Rare): While this spinning purple rhomboid circles your head, you can speak and comprehend 2 random languages stored within. You can spend a year infusing the stone with the necessary words to replace an existing language within.
- Waterbreathing (Very Rare): You can breathe underwater while this pale blue spindle orbits your head.