Arena is the game’s head-to-head PvP mode, split into at least two formats: the standard Glory Arena and a 3v3 Arena. Both maintain their own leaderboard of top players. For building three lineups for 3v3, see the 3v3 Arena guide.
Daily diamond tip
A small but easy daily habit: open the Arena building, visit both the Glory Arena and 3v3 Arena leaderboards, and “like” the top three players on each. Community reports put this at roughly 30 diamonds per like — around 180 diamonds a day for six likes, for well under a minute of effort. It’s a small amount individually, but it’s free and takes almost no time, so there’s little reason to skip it.
Arena lets you pick which squad’s research applies
Before a fight, Arena lets you choose which squad’s research bonus package to use — T1 for Squad 1, T2 for Squad 2, T3 for Squad 3, or T4 for Squad 4. That means investing in Squad 1 research doesn’t just help normal marching; it also improves the research bonus you can bring into Arena. Early on, prioritize your main squad’s research before spreading into secondary squads, partly for this reason.