Tukkin says that the formula for idle mode upgrades is (100% – current Idle Mode speed) / 35. So that means that you get 1/35th of the difference between your current idle speed and 100% every time you upgrade. So it's impossible to truly reach 100%.
For anyone foolish enough to try, Idle mode will never reach 100%. it'll say that it does, but that will be rounding error. The equation that determines how powerful each upgrade is one that approaches 100% but never reaches it until you upgrade infinity times, I believe.
@shadow12984 that glitch is caused by a shange in speed. Most likely he hits one of your team members with a reducing speed spell, then is able to go again because his speed is now higher than yours. The good news is that when the speed spell wears off, your team gets two turns just like he did.
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