Materials can be used to upgrade Towers and Heroes. Upgrading these improves their performance in combat and unlocks new abilities.
Materials can be discovered in the following ways:
- As a reward from completing Missions
- Collected when dropped randomly from defeated Creeps.
- Completed missions can be revisited to collect more Materials
- Gold can be spent to salvage further rewards from that completed mission.
You can tap on a particular Material in the inventory to discover the best missions to find it.