First, let's make sure you understand what splash damage is. Weapons with splash damage create a sphere of pain from their impact point. Players and buildings take more damage the closer they are to the center of the detonation. The way this works is there is a ray trace done from the center of the explosion outward. All explosive weapons have this. Notably, the Direct Hit has a tiny one. So what's the bug, and how can you stop it? Well, first it's not really a bug, because in reality, everything is working as intended. It's just that people making the maps (ie, you and me) don't always take measures to prevent splash damage breaking. Let's have a hypothetical situation. You're a soldier attacking players on a control point. Defending it, maybe. The control point is on a platform raised about 16 units--maybe a block of wood. This happens. Because the detonation happens below the vertical edge the control point rests on, the ray trace that determines where the sphere of damage should be stops there. And that's all there is to it. The people on the point shoot back at you happily, and you die, and lose. The same thing happens on stairs. And on cool looking bridges (Badlands, anyone?). It doesn't matter what the vertical edge is--if it's solid, the ray trace stops traveling forward. That means even a 1u tall brush textured as a hazard stripe around a control point will do this. Now, what can you do about this? It's very simple. Use blockbullets instead of or in addition to playerclip on stairs and bridges and anywhere else this might happen. You can make triangular blockbullets ramps to carry splash up small ledges (like the control point or stairs example), but don't ask me why that works. It just does. Or, simply don't place control points on little raised brushes. Bear in mind: blockbullets will cut vvis like any regular brush, so you need to func_detail it in many situations. This concludes my splash damage tip.