Break the planks next to the symbol and drop down to grab the supplies.ħ/45 This location is marked by two Lambdas. A nearby ladder leads to the cache below.Ħ/45 While crossing the large steam-venting pipe, you'll notice this Lambda on your right. Go down the stairs inside, and you will see the Lambda underneath the gantry. After dropping down behind the wall of rubble near the wrecked blue van, the symbol is clearly visible and marks the location of a supply crate nearby, under the corrugated sheet.ĥ/45 After being fired upon by a helicopter for the first time, go through a nearby blue door partially hidden by a stack of barrels. When passing through, you'll find another Lambda behind the supply crate blocking your path.Ĥ/45 After encountering your first mounted machine gun, you must break the supports on a platform in order to cross a ledge. During your escape from the lab, the entrance to a shaft between some shipping containers is marked with a Lambda symbol. So if you take the data string from your gamestate.txt, and convert the last 11 characters to binary, you'll get a 0 instead of a 1 for each symbol you are missing, and luckily they are listed in order (so if the first binary value was a 0 instead of a 1, you'd be missing the first symbol).Ģ/45 Inside the boarded-up building immediately after jumping over the first moving train is a cache of items clearly marked by a Lambda symbol.ģ/45 This location is impossible to miss. If you convert the last 11 characters of the string into binary (search online for "convert hex to binary"), you'll get 45 binary values representing the state of each symbol in your achievement progress:ġ1111111111111111111111111111111111111111111 The part we're interested in is the last 11 characters, which is all the Fs in our example. For someone who has completed the achievement, the data string will look like this: One of these blocks will have a line labelled "data", which will contain a string of hexadecimal characters.
#Half life 2 lambda series#
Inside you'll see a series of "blocks", each of which represents your progress towards one achievement. Steam\SteamApps\common\Half-Life 2\hl2\gamestate.txt If you go to the directory where you installed Steam, and open the following file: If you've already made some progress towards this achievement, and want to know which symbols you are missing, you'll have to do a bit of digging around in one of the game's files.