Notch Rock is one of the game's resources.
At the start of the game, they will be as important as the Dark Soul Crystals will become later on and it may seem that you're always lacking these, but afterwards you'll have a huge surplus. Just concentrate on unlocking Hard scenarios and center your Level Tax collections on them (they are also the most lucrative by far) and soon you'll have more than enough.
- Battles and Level Taxes in any scenario in Hard Mode.
- The last of daily Online Rewards
- Daily Login Reward
- Some events
- Mysterious Store
- Tower research at the Engineering Quarter.
- Tier 4+ Soldiers Equipment
- Second Training Ground slot and upgrade
- Second Supply Station upgrade
The max stack of Notch Rocks is 999.