When you are hit by a greed or if you drop your belongings, coins are prioritised. But then, if you have no coin left, gems will drop (and then the crown).
Also unlike coins, gems will never fall into the water/river/sea. If a Monarch drops a gem—intentionally, due to the purse being full, or due to a Greed's hit—this gem cannot fall beyond the line of the ground.
Gems stolen by greedlings on an island are recovered after the cave of that specific island has been destroyed: all gems stolen on that island are spat out of the cliff portal with the bomb detonation. The Monarch though must escape the bomb explosion in order to collect them. See related bug.
Gems in the pouch are lost for good if the Monarch loses the crown (or the crowns, in co-op).
Gems dropped in a safe place (at the Town Center of a Kingdom with multiple walls on both sides, for example), are lost for good if the Monarch travels to another island or loses the crown (or the crowns, in co-op). The island may be found again with some walls untouched by decay, but not the gems once dropped there.
Gems spat out of the cave with the bomb detonation are lost forever if the Monarch does not get out in time.
All gems originally come from a gem chest, a fancy coffer found in the forest. For further details, see: Ruins § Gem chest.
It is possible to store gems with a merchant banker that appears by the central wharf. For further details, see: Gem Keeper.
There are nineteen unlockable features, including statues, hermits (with their special tower upgrades), mounts and technologies. They are all listed below along with the number of gems required to unlock them (between parentheses) and the island they're unlocked on. A few that do not require gems are not followed by any number.
The precise amount of gems found on each island is listed on the second column. The total of gems available in all islands is thirty-five, and the amount required to unlock all features is thirty-eight gems, which makes impossible to unlock them all, even if the Monarch lose no gem. This leads the campaign to a situation where well choosing the Kingdom's features should always matter.
|1st||0||Archery (3)||Ballista (3)||Griffin (2) / Gamigin (1)||–||–|
|2nd||8||Scythe (1)||Stable (1)||Stag (1)||Stone||Dog|
|3rd||9||Building (3)||Bakery (4)||Warhorse (2) / Bear (3)
Draft horse (1) / Golem (2)
|4th||9||–||Knight (2)||Bear (3) / Beetle (2)
|5th||9||Knights (2)||Horn (3)||Unicorn (4)||–||–|
|Total:||35||(total required: 38)|
Acquiring a gem by day IX grants the "On the Ninth Day" achievement.
The gems system has been introduced to replace the signpost. People didn't always understand the previous unlock system and, because of it, thought there was not that much unlockable content in Kingdom: New Lands. It was often left locked.
Since version 1.0.1 (Xbox and PS4): There is no way to recover stolen gems.