Races
A monster's race determines which cards, potions and skills affect it. Much of your gear grants damage or defence bonuses by enemy race, so knowing races is the key to efficient farming.
Formless — creatures with no clear anatomy: slimes, mushrooms, elementals, magical blobs. They belong to no "natural" category, so dedicated formless cards work against them.
Undead — zombies, skeletons, ghosts and cursed beings. They cannot be resurrected, and healing spells damage them instead of healing. They especially fear Holy and Fire.
Not to be confused with the element of the same name: the Undead race and Undead element are separate attributes, though they often coincide.
Brutes — animals and wild monsters: wolves, bears, birds, beast-like creatures. The most numerous race of the fields and the main target of early farming.
Plants — the flora of Midgard: mushrooms, flowers, tree-monsters. They often have fixed damage (1 damage from normal attacks), making them safe targets for card farming.
Insects — beetles, bees, spiders and other arthropod fauna. Fast and often poisonous; many of them drop valuable weapon cards.
Fish — aquatic creatures of lakes, seas and underwater caves. They usually carry the water element, making them especially vulnerable to wind attacks.
Demons — infernal creatures, imps, harpies and dark spirits. They often carry the Shadow or Undead element and dwell in dangerous dungeons.
Demi-Humans — humanoid monsters and players themselves. This race is critical for PvP and WoE: anti-demihuman cards (such as Thara Frog or Hydra) form the backbone of combat builds.
All players are demi-humans — which is why these cards are key for PvP/WoE.
Angels — celestial beings of the Holy element. Rare, often bosses; vulnerable to Shadow damage.
Dragons — mighty reptiles and dragon-like bosses. A large race with high HP; many MVPs belong to the dragon race.