These are formulas for predicting both the power and cost progression of upgrades determined in September 2012. The formulas can be found here.

Note: while the current formula used to predict a weapon's upgrade powers uses its Lvl 1 power, it now appears that it's more accurate to use its Lvl 8 power to retrospectively determine its previous power levels (this appears to cause less rounding errors, as demonstrated from the power levels of the Xmax-Tree introduced in Version 2.20).

The **Incremental Costs** tells you the total amount of gold you'll need to spend to fully upgrade a given level from each of its upgrade levels, which is why the costs decrease as the levels increase -- this is not an error.

## Upgrade Formulas

Costs

Level 1: (Purchase Cost) Level 2: Purchase Cost x 0.3 Level 3: Purchase Cost x 0.5 Level 4: Purchase Cost x 0.7 Level 5: Purchase Cost x 1.0 Level 6: Purchase Cost x 2.0 Level 7: Purchase Cost x 3.0 Level 8: Purchase Cost x 4.5 ---------------------------- TOTAL: Purchase cost x 12

Upgrades

Level 1: (Initial Power) Level 2: Initial Power x 1.15 Level 3: Initial Power x 1.35 Level 4: Initial Power x 1.60 Level 5: Initial Power x 1.90 Level 6: Initial Power x 2.30 Level 7: Initial Power x 2.80 Level 8: Initial Power x 3.50