Most top players would test different defensive and offensive formations in the first week of each season. At this time, trophy counts do not matter as much. Use the first week to try new formation tactics and improve on your strategies.
Record and review your battles so you know what works and what doesn't. If you lose a battle by small margin, make adjustment to your formation and try again. Sometimes you have to lose multiple times to find the right tweaks.
Arena is constantly evolving as players find new tactics. Try to find higher-ranking players who use the same heroes as you do, analyze their defensive formations, and try their tactics yourself.
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Arena is constantly evolving as players find new tactics. Try to find higher-ranking players who use the same heroes as you do, analyze their defensive formations, and try their tactics yourself.
When you challenge another player, but do not think you can win, back out of the battle by tapping ⇦ on top-right corner. You will not lose your chances of attacks.
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Use your attacks as late as possible, especially in the final days of a season. If you attack too early, you can become a target to other players.
To get as high rank as you can, you need to do as many attacks as possible. Most high-ranking players do at least 30 attacks each day.
Consider buying a Battle Pass, which gives you 30 free attacks plus 10 gems attacks each day. A Battle Pass is valid only for a season.
Consider use gems to do extra attacks (you need 260 gems for 10 extra attacks).
When you attack a player with a higher ranking, the higher the trophy count the player has, the more trophies you gain for a win (and the fewer trophies you lose for a loss).
Conversely, when you attack a player with lower ranking, the lower the trophy count the player has, the more trophies you lose for a loss (and the fewer trophies you lose for a win).
Your defensive formation may not be what you think, so regularly check your defensive formation.
Your defensive formation may be broken for a variety of reasons
You upgraded troops that are used in your defensive formation, and they have been replaced by other troops.
You accidentally imported your farming formation to your defensive formation.
A game bug reset your defensive formation.
Your defensive formation needs to be ready handle different kinds of attacks. Ask other members in your clan to attack you and record the battle so you know what you can do to improve your defense.