Tank Stars – Upgrades
Each tank is upgradeable, as are each of its weapons. They can be upgraded with weapon cards and coins, which you gain through winning battles and opening chests. Once you’ve gained enough cards to upgrade a weapon, you pay a certain number of coins to unlock the upgrade.
Each upgrade grants a star for that weapon, and there’s a 5-star maximum for any given weapon. These upgrades provide higher attack damage (and occasionally greater explosion range), so they’re useful for facing other players in the game’s PvP mode. Tanks can also be upgraded in the same way (which increases their HP), though the required tank cards are rarer.
A quick way to gain coins and tank/weapon cards is simply to open the game once a day. Free chests are given for the 5th, 10th, and 15th consecutive days of logging into the game, and materials can also be gathered through completing daily missions.
The game has ads, which are an annoyance present in many free-to-play games, but sitting through them can actually be helpful. You can watch a video ad—usually about 30 seconds long—to unlock additional chests and get a free revive if your tank is destroyed in an AI or Tournament battle.