If the champion is supposed to land a critical hit, critrate is needed. 

Sometimes I really can't understand why certain questions are asked. What exactly is your indication that critrate is not needed for void champions?

if you Stats dont say 100% Crit Rate  ... I would say Crit Rate would be needed to be Added

If your Void Champion isn't a Damage Dealer, you don't need C.Rate on it.

You could simply add Defense or Health.

Yes. But obviously that has nothing to do with the champions status as a void. If your force, spirit or magic champion isn't a damage dealer, you don't need critrate. The connection "void = no critrate" is just stupid.

Maybe OP was confused about void affinity champs inability to get weak hits and such. 

Like what the others said, if you're gearing a damage dealer, or a skill indicates that it needs crits to proc, crit rate is still needed. 

I just thought red needed critrate for against green, and green for blue, and blue for red. 

No - you seem to be really confused.

Red Affinity is weak vs. Green Affinity.

Red Affinity is nuetral vs. Red Affinity & Purple Affinity

Red Affinity is strong vs. Blue Affinity.

Green Affinity is weak vs. Blue Affinity.

Green Affinity is nuetral vs. Green Affinity & Purple Affinity. 

Green Affinity is strong vs. Red Affinity. 

Blue Affinity is weak vs. Red Affinity.

Blue Affinity is nuetral vs. Blue Affinity & Purple Affinity. 

Blue Affinity is strong vs. Green Affinity. 

You shouldn't be attacking Affinities that your weak against.

It puts you at a disadvantage.

For Example:

Lets say you have a hero who is Red Affinity.

You want to avoid fighting Green Affinity heroes with that Red hero.

The Green Affinity hero will have an edge over you.

Instead, You want to use your Red Affinity hero to attack Blue Affinity heroes.

This way you will be at an advantage.

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The reason people use Critical Rate & Critical Damage is so there hero can deal more damage.

The game has 4 types of hits

- Weak Hit 

- Regular Hit

- Strong Hit

- Critical Hit

The worst type of hit is Weak hit - It deals the weakness damage.

The best type of hit is Critical hit - It deals the most damage.

If a Red hero fights a Green Hero, you might do a Weak hit 

The Red hero is weak vs. Green hero - The weak hit is so bad 

People try to avoid this match up.

If a Red hero fights a Blue hero, you might do a Strong hit.

The Red hero is strong vs. Blue hero - The strong hit is the second best hit in the game.

People try to make this happen all the time so they have the edge!