The phrase comes from World of Tanks, the multiplayer tank game released in 2010, where Russian voiceover lines report the result of each shot. 'Est probitie' means there is a penetration, confirming the shell went through the target's armor instead of ricocheting. Players heard it thousands of times during matches, so it became instantly recognizable in Russian speaking gaming communities. Clips later spread to YouTube, TikTok and soundboards as a standalone reaction, used far beyond the game itself for any moment that feels like a confirmed hit.