First, the rule change/clarification: Null canceling movement scripts are now explicitly banned, and we will reject any runs using them going forward. Scripting in general has always been banned, but quite a few people still use the null movement alias setup, so I figured it should be clarified that this will no longer be allowed under any circumstances. Now, for the much bigger change:

Beginning on Monday, October 18, 2021 4:00 PM GMT, the proof requirements for top level submissions will be increased to require demos in addition to video. A tutorial on recording demos is given below.

What counts as a "top level submission"?

• For every category (fullgame or IL), top 5 times must have demos and video. HOWEVER:
• For every 20 runs a category (fullgame or IL) has, this threshold increases by another 5 places on the leaderboard.
• The threshold can vary between Solo/Co-op and Any Difficulty/Expert Realism for a given IL/fullgame category.

Which leaderboards does this affect?

• This affects L4D1, L4D2, and the category extensions for both games. For co-op runs that meet the criteria described above, all players in the run must record demos and include them in the submission description. Video is still only required for the host (or whoever loads first if manipulating loads via rate command).

To give some examples:

• For Dark Carnival Solo/Any Difficulty, there are currently 46 runs. This means that any time that reaches top 15 will require demos.
• For Dark Carnival Solo/Expert Realism, there are currently 3 runs. This means that only top 5 submissions will require demos.
• For Dark Carnival Coop/Any Diff, there are currently 23 runs. This means that any time that reaches top 10 will require demos FROM ALL PLAYERS IN THE RUN.
• For Main Campaigns Solo/Any Diff, there are 69 runs, so a top 20 submission requires demos.
• For both All Campaigns Solo categories, there are less than 20 runs each, so only top 5 submissions will require demos.
• The same logic applies to the rest of the ILs/categories.

HOW TO RECORD DEMOS

• To record a demo, write "record DEMO_NAME" in console where DEMO_NAME is the desired output filename.
• One demo will be recorded for each map, and the game will automatically continue to record demos through level transitions and votes to restart/change campaigns.
• HOWEVER, if you disconnect from the server (going to the menu, or using map command) and need to create a new server, then you will need to manually record another demo, and after that, demos will continue to automatically record upon map transitions as long as you don't leave the game again. YOU MUST NAME THE NEW DEMO SOMETHING ELSE OR ELSE THE ORIGINAL DEMOS WILL BE OVERWRITTEN.
• If you run the record command while demos are already recording, it will be ignored and the console will print "already recording".
• To stop recording demos, simply type stop in the console.
• Demos can be viewed by using the playdemo command in the console.

Where do demos record to, and how do I include them in a submission?

• By default, demos will record to the Left 4 Dead 2\left4dead2 directory. You can specify a directory but the folder must already be created for it to work. When you finish a run, put the demos into a zip file and upload them to a permanent file host (such as Google Drive), make sure the link is openable by anyone, and put it in the description of your run on speedrun.com when you submit.

FOR L4D1 v1.0 OR THE META ALL CAMPAIGNS LEGACY ROUTE

• If you need to start a new server mid-run (as described above), record a new demo as soon as possible.
• For L4D1 1.0 ONLY we are going to unban the changelevel command to switch campaigns instead of the map command, as it does not cause the game to break like it does in newer versions of L4D1 or any version of L4D2.
• This means you will not need to start a separate demo recording every time you switch campaigns; simply load into a map (and trigger cutscene skip), start recording a demo, and then changelevel to the first map of No Mercy (assuming you are starting with No Mercy).
• Modify your cycler to use "changelevel" instead of "disconnect;map", and demos will continue to automatically record throughout the entirety of the run.

Conclusion

• In the long term a plugin will be released to automate most of this process, so that demos will continue to automatically record even if you need to use the main menu in the middle of the run. If you have any questions or if anything is unclear, please do ask in the Discord server. The goal of this is not to make running the game harder/more confusing, even though it will probably cause annoyances in the meantime until the plugin is released. We are just doing this to reduce any possible doubt from anyone going forward that the top runs on the leaderboard are in fact legitimate, and also to prevent future cheaters from being able to conceal certain cheats easily. Thanks everyone!