From Scrolls Wiki
Unstable is a trait which deals damage to opponent's idol on the same row as the unit when it is destroyed.
Damage dealt this way equals the figure following the trait.
When [this or enchanted unit] is destroyed, it deals [X] damage to your opponent's idol on the same row.
Scrolls with Unstable
- June 18th, 2014: Added to the game.
- June 3rd, 2014: Added to the test server.
- ↑ http://scrolls.com/2014/06/scrolls-changelog-0-124-starters-sounds-and-more