What - Spellstones are mundane stones with a number of circles inscribed on them that have had Spells (Arcane or Divine) fused into them
Who - Any Player Character (and a few Non-Player Characters) may use a Spellstone
When - Whenever a Caster Player Character could cast a Spell, a Spellstone may be activated
Where - Anywhere a Caster Player Character could cast a Spell, a Spellstone may be activated
Why - Spellstones are designed to allow Player Characters who cannot cast Spells to cast any Spell, but at less frequency than a Caster Player Character could and to let Caster Player Characters cast high level Spells much, much earlier in a campaign than they normally would be able to
Activating a Spellstone - A Player Character clutches the Spellstone with one hand and speaks aloud their own True Name or the name they believe to be their True Name and the Player Character makes a Spellstone Check \ If successful the Spell fused inside the Spellstone is cast (and the Spellstone can be used again after the next Dawn) \ If the Spellstone Check fails, the Spellstone Shatters
Casting Time - 1 Action (which means that Spells that are Bonus Actions take longer to cast and Spells that would take longer than 1 Action take much less time to cast with a Spellstone)
Range - Same as the Spell
Components - All Verbal, Somatic and Material Component requirements are met by the Spellstone
Duration - Same as the Spell \ If Concentration is required the Spellstone automatically succeeds at all Concentration Checks as long as the Spellstone User clutches the Spellstone in the same hand
Spellstone Identify - Whenever a Spellstone is placed in a Player Character’s palm, the Player Character immediately is aware of every Spell the Spellstone can cast (which is every Spell, Arcane or Divine, that has a Spell Level equal to the number of Circles inscribed on the Spellstone that is detailed in any book the Player controlling the Player Character using the Spellstone has been permissioned to use in the game)
Spellstone Shatter - A Spellstone shatters if a Spellstone Check is a roll of all 1s on all Dice used for the Spellstone Check \ A Spellstone Shatter causes immediate Damage to the Spellstone User equal to number of Circles on the Spellstone \ When a Spellstone shatters the Spell intended to be cast does not cast and the Spellstone becomes mundane stone shards, incapable of casting the previously fused Spell ever again
Non-Caster Check - Roll 1d4
Caster (Level 1 to 2) Check - Roll 1d12
Caster (Level 3 to 4) Check - Roll 1d20
Caster (Level 5 to 6) Check - Roll 1d20 and 1d12
Caster (Level 7 to 8) Check - Roll 1d20 and 1d20
Caster (Level 9+) Check - Roll 1d20 and 1d20 and 1d20
Caster Level is Caster Level (Not the highest Level of Spell the Caster can cast)