Swords & Wizardry Appreciation, Seven Magic Items, Day One

Like many others, I'm doing a whole week of posts to celebrate Wednesday's Swords & Wizardry Appreciation Day. I'll post one new magic item per day. Today's item is:

Torquemada's Crown (Magic Item)

Made of iron and crafted in the shape of a crown of thorns, this is a magical interrogation device. Placed upon the head of any human, demi-human or humanoid, the individual wearing it must answer truthfully to any question, or else suffer damage determined by the severity of the lie. The smallest white lie – a lie that could harm no one – will deal 1d6 damage to the individual wearing the crown. A lie which could result in temporary harm to someone does 2d6 damage. A lie which could result in permanent harm to someone will cause 3d6 points of damage. A lie that could potentially result in someone's death will do 4d6 damage. At the GM's discretion, damage dice may be increased or decreased, and saves may be allowed.