Website and data research by 101Leafy.
Fusion
Shin Megami Tensei if...
101Leafy researched how the game picks the result of a fusion. The checks below run in this order, and the first one that fits decides the result.
How a two demon fusion is decided
- Special fusions come first (list below).
- Two demons of the same race: a light race gives a set elemental, and Herald, Megami, Deity, Destroyer, Dragon, and Lady cannot fuse with their own race. A dark race gives a demon of another race whose level is at least the average of the two levels + 2.
- Two light races of one group: each race of the group offers its lowest demon at or above the average level + 3, and the lowest of those wins. When none is that high, a two race group gives the higher of its top demons and a three race group fails.
- An elemental and another demon: the other demon moves up or down its race by the elemental's step for that race. A demon already at the top cannot move up, so the fusion fails.
- Two dark demons: the higher level one moves up one rank. A light demon L with a dark demon D: when L is lower than D, an odd level sum is an accident and an even sum moves D up one rank. When L is at least D's level, a level sum divisible by 7 moves L up two ranks, by 5 up one, and by 3 down one; any other sum works as when L is lower.
- Everything else uses the race chart. The result is the lowest demon of that race at or above the average level + 3, or its top demon when none is that high.
The result can never be one of the two demons fused. A result above the hero's level is refused. After you confirm, a 1 in 256 accident can give a random demon between the hero's level - 10 and + 15. The moon phase plays no part.
Race chart
Light races only. A dash means the pair goes by another rule or fails.
Race groups
Dark races
Special fusions
Elementals
Two elementals give a demon of the race in the table: the highest demon of that race at or below the hero's level, or an accident when there is none. Three of Salamander, Undine, Sylph, and Gnome, or three of Flaemis, Aquans, Aeros, and Erthys, give the demon listed for the one left out.
Three elementals
Sword fusion
The fusion menu can also fuse a sword with a demon, with any demon of one race, or with a second sword, and two swords with a demon. Each card is one sword and what it makes.