Weapon EXP (abbreviated as WEx on this site) is a hidden weapon stat that features from FE5 and onwards. It is the main factor that determines the rate at which weapon levels rise. Contrary to popular belief, weapon Weight is not a factor (it is simply a coincidence that weapons with high WEx values are heavy).
WEx is always 1 in FE5 (except for staves) and FE6, and is always 2 in FE11 (except for the real Imhullu and for Dragonstones, where it is 0). In FE7~10, different weapons and staves have varying values of WEx (around 1~8). For example, the Steel Axe (FE7/8) has a WEx value of 2.
Each time a character strikes with a weapon or uses a staff, WEx is gained. For example, each time you attack with a Steel Axe (FE7/8), 2 WEx is gained. If you double attack, a total of 4 WEx is gained. If you pulled off 4 hits with a Brave Sword (WEx value of 1), a total of 4 WEx is gained. Exceptions to this rule include FE10 where extra attacks from Brave weapons do not add WEx and FE11 where you only gain WEx once per battle, regardless of how many hits are performed.
Additionally, in FE6~8, WEx is doubled for fatal hits (when the hit KOs the enemy). Fatal hits have no effect in FE5, 9-12. For example, if you double attack with a Steel Axe (FE7/8) and kill the foe, you gain 2 + (2 x 2) = 6 WEx (2 for the normal hit and 4 for the fatal hit).
The amount of WEx needed to progress between weapon levels varies between games. In FE5 and FE6, a constant amount of 50 WEx is needed to progress from one level to another. In FE7~10 the amount varies as listed below. FE11-12 have slightly different requirements than the others. To find out more information on weapon level progression, please check the Calculations pages for the relevant games.
|Weapon Rank||Required WEx||Total WEx|
|– to E||1||1|
|E to D||30||31|
|D to C||40||71|
|C to B||50||121|
|B to A||60||181|
|A to S||70||251|
|S to SS (FE10 only)||80||321|
WEx explains how the Devil Axe, Hammerne staff and Eclipse in FE7/8 increase weapon levels so quickly. It is because those three items have a WEx value of 8.
The lack of a fatal hit bonus explains why weapon levels are so difficult to raise in FE5 and FE9. Compare to the GBA titles (which had the bonus) where you can easily get two S Ranks or one S Rank and an A Rank on one character.