Fusion

Fusion is the process by which mods are combined together to create a more powerful mod. Fusion requires at least two mods or a single mod and a Fusion Core.

Fusing mods increases their level and increases the power drain of the mod. The rarity of the mod being fused or used to upgrade another greatly impacts the price. It is generally more efficient to use lower rarity mods to upgrade mods.

Fusion Process
To perform fusion on a mod a player must do the following:
 * 1) Navigate to the arsenal.
 * 2) Click the "Mods" option in the bottom left.
 * 3) Select the mod you wish to upgrade.
 * 4) * When combining mods of the same type, always choose the higher level one first. Choosing the lower level mod first will result in a mod weaker than than you had originally.
 * 5) Select the option Fusion.
 * 6) Select a 2nd mod or Fusion Core
 * 7) Select the option Fuse
 * 8) A popup will appear with a credit cost.
 * 9) Click Yes to continue.

The fusion process is complete and the 2nd mod selected will be consumed. The energy will be added to the mod. If the energy level is full, the mod will upgrade.

To apply fusion to mods that are already equipped, navigate to the weapon, warframe, or sentinel that the mod is equipped on, then press the "Mods" button within that menu. Equipped mods will appear first in the list of mods with a blue icon in the bottom right corner.

Fusion energy in simple terms

 * Fusing an unranked mod with the same unranked mod provides enough energy to result in a rank increase.
 * Fusing an unranked mod with a different unranked mod of the same polarity and rarity provides one half of the energy needed for a rank increase.
 * Fusing an unranked mod with a different unranked mod of a different polarity and same rarity provides one quarter of the energy needed for a rank increase.
 * Rarity of a mod increases both the energy required for a rank and energy provided.
 * A uncommon mod provides and requires 2 times as much energy as a common mod does.
 * A Rare mod provides and requires 3 times as much as a common mod does.
 * Every next rank-up requires twice as much energy as the previous rank-up did.
 * Every rank provides an additive 50% bonus to the mod's energy value.
 * Fusion cores are counted as all polarities.
 * To bring a rank 4 uncommon mod to the next rank we would need to fuse it with either:
 * 16 unranked mods of the same kind.
 * 32 unranked uncommon mods of same polarity.
 * 64 unranked uncommon mods of a different polarity.
 * 2 rank 6 mods of the same kind. (an obviously wasteful fusion)
 * 64 unranked common mods of the same polarity.
 * 128 unranked commom mods of a different polarity.
 * 64 rank 2 common mods of a different polarity.

Fusion Efficiency
Three parts: Energy required for upgrade, energy offered by mod, and modifying ratios.

The energy required to increase the rank of any mod is dependent on its current rank and rarity.

$$E_{r} = 4 \cdot R \cdot 2^{r}$$

Where:
 * $$E_{r}$$ = Energy required to upgrade from previous rank
 * $$R$$   = Rarity (Common:1, Uncommon:2, Rare:3)
 * $$r$$    = Current rank (white ticks)

The energy offered by a mod is dependent on rank and rarity.

$$E_{o} = 2 \cdot R(2 + r)$$



Where:


 * $$E_{o}$$ = Energy offered
 * $$R$$   = Rarity(Common:1, Uncommon:2, Rare:3)
 * $$r$$    = Current rank (white ticks)

Finally the energy transferred is affected by the polarity and type of mod.
 * Fusing a duplicate - 100% (1 duplicate required to reach level 1)
 * Fusing of matching polarity or fusion core - 50% (2 matching polarity Mods to reach level 1)
 * Fusing unrelated - 25% (4 unrelated Mods to reach level 1)

Mod Credit Cost
Common mods base price is 300, plus  150 times its level for cores. To upgrade any existing mod you need credits and cores or other mods. When using cores, consider this:
 * Uncommon mods base price is 600, plus  300 times its level for cores.
 * Rare mods base price is 900, plus  450 times its level for cores.

Example
To fuse a common core of level 3 would cost 750 to fuse. A rare core of level 5 would cost 3,150. When a mod would only be the base price.

Implications
The best fusion energy/cost is to be found in fusing Rank 0 duplicates into a single higher ranked card. The second best ratio is tied between fusing matching polarity rank 0 mods and fusing any Fusion Core. The worst ratio is in fusing rank 0 mods of a different polarity than the mod being raised.