Merge Mechanic

How It Works

Players have 2 ways to merge towers:

  1. Map to Map drag: Hold a tower already placed on the map for about 1 second (long press) → the tower enters a draggable state → drag it onto the target tower to merge
  2. UI to Map drag: Drag a tower directly from the tower bar in the UI onto a tower already placed on the map

The merge result is predetermined by MergeRecipeData (JSON) — each pair of towers A + B can produce a stronger tower C. Players can only execute a merge when they have the required components in their loadout.

Tactical Impact

With 5 basic towers carried into each match, players aren’t limited to just those 5 types. Through merging, a new tower tree opens up:

  • Power vs. Path Control: Merged towers have superior stats, but come with a resource cost and tactical risk. When two towers on the map are combined, the player loses one Blocker — this can completely change the enemy’s path and break the established maze structure.
  • The Core Dilemma: Should you maintain tower count to control pathing, or sacrifice a strategic position to create concentrated high firepower at a single point?
  • Recipe Discovery: Not every tower pair has a merge formula — this encourages exploration and experimentation in every match.

Technical Challenge

The long-press + drag mechanic requires clear disambiguation between: a normal tap (select tower), a long press (begin drag), and drag release (execute merge or cancel). The entire state machine is handled by GameController.cs and CrystalPlacementController.cs.