As discovered by the Steam Database Twitter, a recent update to Dota 2 included a number of files that reference things like an RPG, ziplines, and procedural spawning. The most intriguing file with obvious half-life implications is titled hl3.txt, which has lines like:

• “Attribute.prop_zipline.max_ride_speed”
• “NPCs that are in the same squad (i.e. have matching squad names) will share information about enemies, and will take turns attacking and covering each other.”
• “A permanent squad member cannot leave the player\’s squad unless killed or explicity removed by entity I/O. Only use this if you\’re sure you want to override the default AI.”
• “If you want your citizens to squad with the player but not obey commands the player gives to move the squad, put a concept here and this citizen will speak the concept instead of obeying the order.”

If you don’t want to pull the files from Dota yourself, you can find the full uploads here:

• hl3.txt
• rpg.txt
• ai_basenpc.txt

Are any of this a reference to possible features in Half-Life 3, and were the files just “accidentally” dropped into a Dota 2 update?

Probably not.

But judging by the number of “It’s Happening” (and “It’s Not Happening”) gifs on the Internet right now, everyone still wants to believe.