Lag and Latency, not a glitch or a bug. Information is sent in 'packets' over the internet. These packets only have a set time of validity, they can be late but not too late. Lets say you're standing there watching an angle or corridor or whatever. You realise you are taking damage from someone to your side you didn't see, you retreat around a corner and wait for your shield to come back. A few seconds later you die, and you see it was a guy who could not possibly get an angle on you. You assume you were shot through a wall. However, the packet containing information on the bullets the other guy was firing, or the damage you were taking from it, were not reaching the Host in time. The view from the other guy: He saw you and knew you hadn't noticed him, he had the advantage. He also knew his current weapon could kill you in 4-5 shots. He shoots you 5 times, 6, 7 and you don't die. At that point you run and hide around the corner. The packets containing the relevant information were likely delayed (latency) or some of them were so late they were not accepted and the data contained not applied (lag). So you believe you were safe, but as the data catches up the game (netcode) decides you should be dead and so you die. This is frustrating for both players, the other guy knows you should have already been dead and you think you've been shot through a wall. And yes, it will actually sometime look like it too but that's the Predictive Rendering, this is a tool in place that tries to fill in the data gaps on screen so you don't notice and have a smoother experience. I don't like it personally, without it we would see a much more accurate representation of whats really happening. This is just a basic description, there are far more complexities than this but I wanted you to know that you CANNOT be actually shot through walls. The network model is the first problem, and while Bungie are constantly improving the netcode it will neven be perfect. The next problem is players' connections. So many people think its not their problem when the truth it that it is. People quote speeds when they are not a good measure of connection quality, people quote ping when its just a measure of the latency to a local server and does not represent connections to other players. And worst of all people try to defend WiFi when they clearly have no idea how much interference WiFi is susceptible to. Tl:dr. The problem is the network model and players internet connections. What you describe is just as likely to be your own connection as any other explanation. Check your connection, portforward, get off WiFi stop downloading midget-prons while playing and it should improve.