The merge spell allows the caster to take any to similar items(or people) and merge their mind, souls, and bodies. If used on items, the more powerful item becomes dominant but has small properties of the other item(i.e. if a sword of sharpness +3 and a sun blade +4 were merged it would have the main attribute of a sun blade but would also be able to slice limbs as a sword of sharpness.) If this is used on two people, they must be of the same race and sex. The person with the higher Wisdom plus Constitution plus level become the dominant mind. (i.e. A mage 4th lvl WIS 12 and CON 14 would dominate a cleric 2nd lvl WIS 15 and CON 11. This would make a mage/cleric lvl 4/2 with everthing mainly that of a mage, like saving throws, thaco, etc.) If the numbers equal each other what happens is a character that is schizophrenic.the reverse SPLICE can be used to severe one person or item into two equal halves. The bad part about this is that if the two halves ever meet they are reunited and jettisoned to limbo.
The material compnet for this spell are the people or items to be merged. Be careful with this spell, it can backfire reall easy and I encourage DM's to be very creative when a player uses this spell.