There is a fan-made system I made up.
Melee: For any slimes which do damage with rolls, headbutts, or slams. (?)
Ranged: For any slimes which do damage with arrow spitting, table flipping, or rocket jumping. (rocket jumping is where a slime shoots a rocket to propel themselves)
Magic: For any slimes which do damage with ice balls, tornadoes, or even magical rockets!
Healer/Radiant: For any slimes which do heal others (and maybe damage, and yes I am also adding HP onto slimes) with life drain (aggresive), powering up stats (passive), or making slimes attack tarrs (aggresive).
Melee beats Radiant because punching is unholy.
Radiant beats Magic because
random reasons. magic is like healing. Also, wizards do not hurt priests I think.
Magic beats Ranged because they can create barriers and reflect arrows onto ranged enemies.
Ranged beats Melee because you can't punch an arrow or a bullet, you can try, but it would be painful.
Alchemist: For any slimes which do damage with Photon Stars (yes, this is all about science), Flasks, or maybe even BOOKS!
Nature: For any slimes which do damage with (NOTE: NOT MAGIC) cursed bellows, ichor slides, or purifying flowers. (Yes, this class, nature, is for anything which does Corrupt, Crimson, or Hallow attacks)
Abyss: For any slimes which do damage with skeletal bones, phantom creation (I'd rather not say it's summoner), or becoming wereslimes. (THIS CLASS IS FOR DOES WHO ARE EVIL DARK)
And possibly lastly...
Summoner: For any slimes which do damage by summoning anything like Shadowflame Balls, Sketch Slimes, or more TARR.
Alchemist beats Nature because science ruins everything.
Nature beats Abyss because NATURE IS THE LIGHT OF DAH DAY.
Abyss beats Summoner because this.
Summoner beats Alchemist because you annoy and distract people and make them cause disasters.
Note: It is hard to think of a new group. So these are the groups for now. However, I have some:
Hunter: Consists of traps. Reference to Huntress.
Aura: I would like a better name like "Monk" but that's stupid. Consists of epic AURAS!
...Mechanic? Or is this Alchemist once again?: Consists of LAZOR BEAMS AND WIRING STUFF!
Squire Slime: Attacks by charging INTO THE PLAYER AT FULL FORCE!