Quoted from RonSS:
So, if 1 millisecond is 0.001 seconds, then 10 milliseconds would be 0.01 seconds.
You are telling me that 1/100 of a second is going to totally screw you up? I'm not trying to be a jerk, I'm actually curious about this.
Voice latency for TV seems to be acceptable well past this number (150 ms), as a reference.
The standard for most games, especially fighting games, is 60fps. That makes a frame roughly 16.7 milliseconds. The native input delay on an arcade cab running Street Fighter 2 is a little over 4 frames (this is in part due to the 60hz refresh cycle of the monitor, also the reason 60fps became the standard). So that's normal and fine, people are use to that.
Add another frame of input delay on top of that and some sensitive players may notice somethings not working quite as expected, but that's not too hard to deal with. Once you start going beyond that though it does create issues.
Don't confuse this with reactions times. If you have good visual reaction times you probably need 200 ms to respond to a stimuli. But that's not the same thing as noticing a delay between a button press and an action, or noticing your combo is dropping because the timing is off because of lag. People can't react to a single frame of data, but they can notice it, big difference.