Can someone explain how lying on the ground invincibility works

[Mishiero]

I was playing as Lucina against my brother, and sometimes when I combo him it results in his character lying on the ground. I then go and do a forward dash attack to get him into another combo. But sometimes it doesn't do anything and sometimes it hits. Can someone explain to me how this works?

 

[Splotim]

You are invincible once you start getting up from the ground. It’s also possible that he is teching (pressing doge right before he hits the ground).

 

[Mishiero]

You are invincible once you start getting up from the ground. It’s also possible that he is teching (pressing doge right before he hits the ground).

But doesn't teching make you instantly recover on your feet? When I advance he's just lying down and I attack, I just go right past him, and then he recovers up and punishes me.

 

[REV3L]

hes timing it so that when you go to attack hes getting up which activates the invincability frames until hes fully stranding again and can act

 

[Mishiero]

hes timing it so that when you go to attack hes getting up which activates the invincability frames until hes fully stranding again and can act

So would a good counter be, go in for an advance and then air doge back to fake him out, and then go for the real push?

 

[Mogisthelioma]

As you get up you become shortly invincible. If he's teching, he'll get back right up on his feet with zero invincibility. But if he falls down, he must be timing his get up at the right moment to dodge your attack. If he continues doing this, predict it. Instead of attacking right away, wait a moment for him to get up, and then punish him.