During a Raid, you can "End Battle" even after the countdown has begun without losing Trophies as long as you haven't deployed Troops and the button does not say "Surrender".
You get 1 star for destroying an opponent's Town Hall. At that point you may claim victory and end the battle with 1 star, or continue battling to earn the remaining 2 stars. You get another star for 50% total damage. You get the third star for destroying everything (walls not included).
Barracks will produce Troops while you're Raiding an enemy village. Start production for your next battle before you begin a raid.
Even if your attacking Troops survive the battle, if you actually deployed them to the battlefield, then you will still need to replace them.
You can tell if the X-Bow is pointed to ground only or air and ground and full or empty by the different graphic. See X-Bow for images.
Raiding people with high level Town Halls gives you more chance for loot, but gives them the opportunity to "Revenge" attack you later.
The Lightning Spell can be used to take out or weaken a defense or Heroes, or take out Clan Castle troops once they are outside of the castle.
Clan CastleTroops surviving a defensive Raid will return to your Clan Castle at full health, even if they were damaged during the attack. Clan CastleTroops deployed as part of your own attack will be lost regardless of whether they survive the battle or not. If you kill the Troops from your opponent's Army Camp, they will return to you as Elixir.
Multiplayer matchmaking is based on Trophy count only. Enemy levels and capabilities will vary widely.
You get a 12-hour Shield if your Town Hall is destroyed, or if 40%-89% of your buildings are destroyed. The Shield increases to 16 hours if 90%+ is destroyed.
Upgrading your Resource Collectors stops production, and they won't begin to collect until they are completed.
If only 40-49% of your buildings are destroyed (not including Town Hall) you gain a 12-hour Shield with no loss to your Trophies. (Use this time to upgrade defenses.)
Defensive Buildings are rated in damage per second rather than per shot; therefore slow firing Defensive Buildings like the Mortar have high damage per shot and yet have a relatively low damage per second rating. This does not mean they are not important.
You can move your buildings/walls/decorations during building/upgrading.
Players cannot Raid your village while you're online, though the game times out if not touched for a period of time (even if your iDevice does not go into screen lock).