How would one define a retro or classic game?

[Lizard]

In my opinion it's any game that was released on a platform that's not in support anymore (windows versions for PC's). For example current gen is Playstation 4, previous gen was PS3 but the PS3 is still supported with some games now and then. So PS2 and earlier are now retro. That's how I judge them.

Wow that really knocked it out of the park. This is a fantastic way to look at it and it's also a very simple way too however there is a small problem; windows vista had it's support ended in April 11, 2017 and I doubt people will consider windows vista era games to be 'classic or retro'. I mean, that would tactically make Doom 2016 a classic game for example unless a game must be unsupported on every platform it was ported too (i.e. doom 2016 was for ps4/xbox one/switch which are all still supported).

This was almost perfect.

[Astraea]

In my opinion it's any game that was released on a platform that's not in support anymore (windows versions for PC's). For example current gen is Playstation 4, previous gen was PS3 but the PS3 is still supported with some games now and then. So PS2 and earlier are now retro. That's how I judge them.

[CuppaJoe]

This really comes down to perspective. A young person born in 2000 might consider seventh gen consoles to be classic or retro, but a person born in the 80's wouldn't.