WAR THUNDER
Install custom sights
A custom sight is a set of reticle element settings in a .blk file. It is not an image: this configuration file controls the sight's look and behavior in game.
Video guide
Step-by-step guide
Find UserSights
Open the War Thunder save folder for your profile. Current paths:
Windows: C:\Users\username\Documents\My Games\WarThunder\Saves\GameID\production\UserSights Linux: HOME/.config/WarThunder/Saves/GameID/production/UserSights Mac: Users/username/My Games/WarThunder/Saves/GameID/production/UserSights
Replace GameID with your profile ID. If UserSights is missing, create the folder manually.
Identify the vehicle
Check which ground vehicle the sight is intended for. For one vehicle, create a folder with that vehicle ID inside UserSights. If it supports several vehicles, use all_tanks.
Place the .blk
Copy the sight file into the correct folder:
...\production\UserSights\<vehicle ID>\Astolfo.blk or ...\production\UserSights\all_tanks\Astolfo.blk
Restart the client
Restart the War Thunder client. In the hangar, select a ground vehicle.
Select the sight
Open Game Settings → Main Parameters → Ground Battle Settings → Sight Settings. In Reticle, select the custom sight and press Save.
If the sight is missing
Check GameID, the exact UserSights name, vehicle folder and .blk extension, not .blk.txt. The file must not be one level too high or too deep. Restart the client after correcting it.
Official source: War Thunder Wiki
Verify an edited BLK
In a test drive, Alt+F9 reloads an edited sight file. Check text, circles, brush thickness, hatch gaps and fill holes. The editor canvas does not prove in-game rendering.