check out uchocolatealmondfudge ' s post <| sep |> HL 3 has absolutely been explored by Valve , maybe multiple different times , but we can ' t say it ' s been confirmed to be on track for release . L 4 D 3 seems slightly more likely . Reminder that Valve views their games as a service rather than a strict product . If there ' s nothing for a new game to offer just another story game then they prob won ' t pursue it at this point . They could have madepublished 10 HL episodes by this time and made millionsbillions off that , but they clearly don ' t feel the need to . Steams success during HL 2 episodes development probably had an impact there . <| sep |> Thank you , that advice is really helpful , one more quick question can you recommend or tell me the kind of equipment you got for your sons fighting robot that your working on or the LED lights , that seems more specifically the kind of things I curious in learning and making with the printer .