Introduced in Update 0.7.6, the Arsenal replaces the old Ranked/Clan Battles reward ship system. Various other items can also bought here.
Coal can be earned through containers. Some challenges and combat missions may also give coal.
Steel can be earned through ranked and Clan battles. Supercontainers can also contain Steel.
1 Steel can be converted to 10 Coal, but Coal cannot be converted to Steel. Along with the more limited availability, this makes Steel a more precious resource than Coal.
- Ships. Some ships can be bought for Coal; others are only available for Steel.
- Special upgrades. These can all be purchased for Coal. Standard and unique upgrades are not sold here.
- Signals. All combat and regular economic signals are available for Coal in lots of 20.
- Camouflages. A selection of camouflages is available for Coal in lots of 20.
- Containers. Various special event containers are available for Coal in lots of 5.
Coupons can be used for a one-time discount on a purchase in the corresponding category. Only one coupon can be used per purchase.
Some (but not all?) coupons refresh after a while after being used. Unfortunately, there is currently no display of the refresh time before the coupon is actually used.