Interesting. I would have thought such an ability would be implemented by increasing the HP on the server and then sending the new HP value to the client. But perhaps this is impractical for some reason.
I think it's a matter of network performance, and the visual bugs that you can create without due care in such a fast-paced online game.
Valve have commented on this hero's mechanics, and issued fixes relating to client/server-side interactions within the past year in fact. But apparently, the exploiuts still exist.
Their comments have been around how redoing such mechanics can cause undue lag between clients that need to be 'caught up with' as quickly as possible. Too long and a client could see something they shouldn't and get a competitive advantage. Valve don't want to have a server updating 10 clients on 10 different network connections if they can avoid it. The compromise is to do more client-side, but that leaves the system vulnerable to such exploits.
Considering that the game includes fog of war, and invisibility mechanics, visual bugs from these systems do crop up a fair bit.
Normally stuff like that would be done both client- and server-side, but the server would have the final say for shared game state purposes (which the client can of course ignore, but then it'll just desync).
I'm wondering what the client vs server is responsible for. I would have thought the server could have been responsible for adding/removing the buff where necessary.
Curious as to how health regen is done in general. The server must have some sort of understanding of what it should be otherwise clients could set it to whatever they want.
