I have a CS server, and I went on and tested a rather large map.. and my ping was great, until I used nightvision in a dark large room, or anywere, then it jumped 300 or 400 and my buddy logged in and started at around 150 ping and jumped to about 800, although Most the map isnt done and some lights arent installed (fear that lights would hurt ping more) I read around and found that if you merged vertices on the walls, so they fit smoothly at a corner, this helps lag? is this right? and how could I do it if so, I use hammer but Iam new at it. Iam making a department store, and the close peremiter outside of it, for a map, i figured id start wall by wall first, got a basic blue print going, and got hit with this problem, so I dont have "skyboxes" or anything outside.. and no, I didnt hollow a giant box to make my level.