I found many other topic and guide to porting Arma2 content to Arma3, but all these about units or maps, not MISSIONs.   So I start this topic to discuss how to convert missions from Arma2.   First thing first, I'm a beginner in this and I have more questions than advises. Don't start to porting missions if you are not familiar with Arma2 mission making and Arma3 mission making process!   0. I used CUP units for Arma2 and AiA maps. 1. I copied the arma2 mission's folder into arma3 missions folder. 2. I open the mission.sqm in an editor and change version=11 to version=12 3. I replace the old unit names to CUP classnames. Eg. USMC_Soldier_SL to CUP_B_USMC_Soldier_SL 4. I replace these classnames in the sqs and sqf scripts too. 5. I try to open the mission in Arma3 editor. If it complains to missing classnames, I find it in mission.sqm file and replace it to a CUP classname, or - if it's not exists - I try to find something similar. Maybe a classname from vanilla Arma3 ? I do it until editor can open the mission without warnings. 6. I try to preview the mission (play the mission) in mode where I can see the script errors on the screen. If any script drop an error message, I find it in the script file and try to solve it with googling for solution. Eg. like no more commands setVehicleInit or processInitCommands, so need solution to make the script working without these. It's a good start to looking for a newer version of that script. Eg there is an Arma3 version of good old UPSMON script. 7. Change to old briefing and tasking system to new one. 8. Remove the A2 healing system.     I know it's too brief and there is a lot of specific questions. I guess this topic is a good tart.   I got questions, so I start a FAQ here:   Q: Do the scripts from A2 still work? A: Some of them yes, others not. Actually most of them will work under A3, than from A1. There are a few script command what is removed (it mentioned above). So you have to check all the script you used in a mission manually and one by one. If you used in A2 a third party script (eg UPSMON), the best solution to ask the original author and maybe there is an A3 version. But if the script was created by you, you have to check it line by line. What will not work in A2 scripts in A3: the A2 animations, some of the A2 classnames (you have to replace the CUP classnames), the A2 first aid module, most of the A2 other modules...etc