Crit %Follow

Can someone clarify for me how crits work? I'm looking at some of the talents and i dont understand how they are useful. Incineration, for example is a 4% increase in critical strike chance. 4% doesn't seem remotely useful. A 4% chance to do anything is basically the same as no chance.

I know there must be somthing I'm missing here, can anyone explaine how chances that low are actually helpful.

There is a chance for everything. 4% is wow is alot more if you actually watch your damage output. I can greatly notice the difference between 25% and 30% in my dps.

Crit increases your base damage by 50% i believe. There are other talents that will increase this more. For example in the frost tree, ice shards increases crit strike damage bonus by 100% when filled out, so instead of the normal 100% damage you would be doing, you are actually doing 250%? damage iirc.

Crits are vital to a mages dps no matter what tree you decide to spec into. As fire your crit should be around 25-30% and as frost 15-20%.

200%.

It's a 100% increase to the bonus damage. Which is 50%. 100% of 50% is 50%. 50% + 50% is 100%. Add in the original 100% and you have 200%.