I'm sure there will be multiple replies to this post - but here's what I can tell you from my understanding.
Whan a wizard attacks or heals (including pets that cast unicorn) and that number (in damage dealt or healing given) is higher than another wizard's cast spell, than it generates threat on the enemy, i.e. it peaks their interest and you become a target.
Reduce threat would mean that the number from the spell you cast is reduced for the enemy - it doesn't mean you do less damage or healing, it will just appear this way to the enemy.
EXAMPLE:
Wizard 1 casts unicorn and heals 375 health in each wizard
Wizard 2 casts tower shield
Wizard 3 casts storm blade
Wizard 4 passes
-Wizard 1 has generated a higher number than all the other wizards and will, therefore, increase threat on the enemy, even though they did not attack.
Say the Enemy was Targetting the First Wizard, the other Wizard would use Reduce Threat on Target on the Enemy, then the Enemy would be less threated by the First Wizard and probably will Target another Player.
If the Second Wizard used Increase Threat on Target, then the Enemy will probably be more Threatened by the First Wizard,
This i just what i thought, tho. Sorry if i am wrong.
I wondered what this meant for years-- I finally figured out what it meant when I got Snow Angel.
If you increase your threat, or 'taunt' them, it makes the monster more likely to attack you, as a grumpy person would if you provoked them. In the same way, if you complimented the grupy person, or reduced your threat, they would be less likely to 'want' to attack you. So if your friend is almost dead and they're only attacking them, you can use a taunt card to make them attack you instead, giving your friend a chance to heal, or vice versa if you're the one nearly dead.
well reduce threat means it doesn't hurt you that much . for example. A wizard your battling uses reduce threat on you then your spells are weaker to the enemy. like he uses the spell reduce threat on you then you use storm shark witch takes 375 away it will not take that mutch it will take about 245 or 275 got that okay hope i am rite and you understand and if i am not rite its ok so cya wizards oh btw by the way i am a lvl 30 fire wiz named cameron thunderflame ok :D hope you enjoy :) cya
In the same way, if you complimented the grupy person, or reduced your threat, they would be less likely to 'want' to attack you. So if your friend is almost dead and they're only attacking them, you can use a taunt card to make them attack you instead, giving your friend a chance to heal, or vice versa if you're the one nearly dead.