Each obstacle that is removed will have 0-6 Gems. The distribution is not random and follows the following repeating sequence: 6, 0, 4, 5, 1, 3, 2, 0, 0, 5, 1, 0, 3, 4, 0, 0, 5, 0, 1, 0. This means on average, each obstacle cleared has 2 Gems. This pattern does not include the 25 gems held from the Gem Box, or the holiday themed Obstacles like the various Halloween Obstacles (2014~2016) which have Elixir; the X-Mas Trees (2012~2016) have Gold instead.
Vegetation respawns at a rate of one item per eight hours, except if all the spaces in your village are totally filled. Furthermore, an obstacle will only spawn if there is a 1-tile buffer zone between the spaces in which it will spawn and another building or obstacle.
Rocks do not respawn once they are removed.
You can't place buildings on obstacles.
Since vegetation respawns, and removing one may have Gems, removing vegetation regularly can be an unlimited (although slow) source of Gems.
If you accidentally set a Builder to remove an obstacle it is possible to cancel if tapped before the Builder is finished.
Cancelling the removal of an obstacle will refund you 100% of the resources spent. Cancelling an upgrade returns only half of the resource cost.
Your village can have a maximum of 44 obstacles at one time. This doesn't include holiday themed obstacles.
There is an achievement called "Nice and Tidy" which gives players Experience and Gems for removing [10/50/500] obstacles.
Troops can be spawned beside and/or on top of obstacles.
After the Halloween 2014 update the required time to remove all obstacles except Mushrooms has been reduced.
Les coffrets de gemmes font partie des obstacles dans Clash of Clans. Ils apparaissent aléatoirement, pendant que vous êtes déconnecté; en moyenne une fois par semaine. Ils coûtent 1.000 à supprimer, mettent 30 secondes à se supprimer, rapportent 5 et 25 .
Leur apparition ne dépend pas du niveau du joueur ou de quoi que ce soit. Ils sont un excellent moyen d'économiser des gemmes pour se payer des ouvriers ou des boucliers. Ils n'apparaissent qu'une fois par semaine, il est possible de se faire 100 gemmes par mois uniquement grâce aux coffrets.
When the Gem Box was added it was quickly deleted due to a few glitches relating to how many Gems it gives. The Gem Box was added back into the game on April 9, 2014, the update that added Clan Wars.
You can only have 1 gem box at any time in a village.
The gem box is rare, but in the April 2014 update their spawn rate was increased.
Note that all special obstacles (and the Gem Box) ignore the one-tile buffer zone rule that governs where normal vegetation can spawn. They can spawn in any 2x2 empty space within your village, though they tend toward spawning close to the outer edges of the field.
During the Winter 2012 Update, they added a X-Mas Tree that gives 30,000 Gold when cleared, which was then increased to 50,000. On 3 January 2013, Supercell indicated on the forums that people will get to keep their trees even after the winter theme is gone. The 2012 X-Mas Tree appears as a small tree with flashing colorful ornaments.
There's a 2012 edition of X-Mas Tree in the far left edge of the map in Gold Rush mission in Single Player Campaign in the line of trees that are surrounding the map, 2013 edition of X-Mas Tree in Gobbotown mission and the 2014 edition of X-Mas Tree in Fool's Gold mission.
During the Winter 2013 Update, they introduced another X-Mas Tree that gives 75,000 Gold when cleared. The 2013 X-Mas Tree appears as a small tree with golden garlands, a golden spike ball on top, and two skulls at the bottom of the tree.
During the Winter 2014 Update, Supercell introduced an X-Mas tree that not only gives 75,000 Gold when cleared, but randomly spawns wrapped presents worth 5,000 Elixir each when cleared. The 2014 tree is similar looking to the 2012 one, but is adorned with tinsel, candy canes as well as colored ornaments and flashing lights.
The present can also be generated by the Santa's Surprise and Santa Strike.
During the Winter 2015 Update, they introduced an X-Mas tree that gives 75 000 Gold after cleared. This tree appears like black metal tree with golden chains, spikes and spiky ball on top. There also lays sword next to it. When zoomed, you can see sparks coming out.
During the Winter 2016 Update, they introduced an X-Mas tree that gives 75 000 Gold after cleared. This tree has red ribbons.
There's a special kind of Army Camp in the Goblin Gauntlet mission in the Single Player Campaign that only consists of a camp fire with different surroundings that the one in the Army Camp, which is only 2x2. You can notice this by the other obstacles that are next to the camp fire. You can also drop troops over it since it is considered as an obstacle.