It doesn't have to generate a lot of traffic, it's just a different imput system. Instead of the server randoming hit or miss, the client just sends a hit to the server if it's a hit, and miss if it's a miss. The hq movement idea is nice, but that requires a very high server load. It could also just be aiming like in a first person shooter, and if you cast an attack, the server will get a message, and also for hit or miss. The attacks still are default ones, but the combat is much more entertaining.