Game developers are gamers, too, so it's not surprising to see them reference each other's games. The people behind Assassin's Creed are notorious for this, dropping both "It's-a me, Mario!" and "pride and accomplishment" jokes in their games. But for every obvious reference, there are more obscure ones that many of us miss. Like a when a certain space strategy game references one conversation in a different space RPG.
Stellaris is the strategy game in question. It puts players in charge of a civilization that just developed faster-than-light travel. Players get to choose how to use this technology. They can peacefully explore or make war to forge an empire that even Darth Vader would find impressive (most impressive, even). Stellaris released in 2016 for PC, but is seeing renewed attention after it launched this February for consoles.
One Reddit user discovered a vey detailed easter egg in Stellaris. One that you wouldn't recognize unless you're very familiar with Mass Effect 2.
In Mass Effect 2, players can find the speech giver in the Citadel docking bay. He's a military commander addressing some trigger-happy recruits. He reminds them of Newton's First Law, that an object in motion stays in motion until acted upon by an outside force. In that case, he reasons, missing a shot in space means the shot just keeps going. He says:
"Once you fire this hunk of metal, it keeps going till it hits something. That can be a ship, or the planet behind that ship. It might go off into deep space and hit somebody else in ten thousand years.
If you pull the trigger on this, you are ruining someone's day, somewhere and sometime. That is why you check your damn targets! That is why you wait for the computer to give you a damn firing solution! That is why, Serviceman Chung, we do not "eyeball it!" This is a weapon of mass destruction! You are not a cowboy shooting from the hip!"
Going back to Stellaris, we see that the "Glancing Hit" event has the player's ship getting hit by a random space projectile. One that was apparently misfired in a "neighboring galaxy" and traveled for years until finding its way onto the hull of the ship. It seems Serviceman Chung missed so badly he hit someone in another game.
Whoops.