How fusion works?

[SkeL]

How exactly fusion works?
What I know so far:
• You can only fuse weapons with the same tier or one tier below. (Green + Green/White or Blue + Blue/Green... etc)
• When you fuse a weapon it get +1 star.


What I don't know?
• What if I fuse weapons at max level (Do I get only +1 star or something more?)
• Fusing can increase the rarity of a weapon?

[Beridok]

TL;DR = Fusionincreases possible max level. Does not include rarity.
Only worth upgrading violet and orange weapons (orange first, it's rarest - however bear in mind that some weapons are simply trash).

Stars / Rarity

A Green 1-Star 5.56 Autocannon and a Green 2-Star 5.56 Autocannon that are both level 1 will have the same damage. Star level only dictates the maximum level of a weapon, but a weapon with better rarity will have more damage at level 1.

The rarities are Common - Uncommon - Rare - Epic - Legendary

Fusion

To fuse weapons, they need to first be max level. The rarity of weapons does not matter when combining them, so save a few common 2-Stars and 3-Stars, and I would save ALL 4-Star and above weapons you may obtain.

1-Star ★☆☆☆☆☆ - 10 max level
2-Star ★★☆☆☆☆ - 20 max level
3-Star ★★★☆☆☆ - 30 max level
4-Star ★★★★☆☆ - 40 max level
5-Star ★★★★★☆ - 50 max level
6-Star ★★★★★★ - 60 max level

Fuse 2-Star = level 10 weapon + 1x any 1-Star weapon
Fuse 3-Star = level 20 weapon + 2x any 2-Star weapon
Fuse 4-Star = level 30 weapon + 3x any 3-Star weapon
Fuse 5-Star = level 40 weapon + 4x any 4-Star weapon
Fuse 6-Star = level 50 weapon + 5x any 6-Star weapon

Source: https://steamcommunity.com/sharedfiles/filedetails/?id=2610322859