[kuschku]

They did, and many games actually used to do that.

But it's a simple issue of economics:

- you can't have cosmetic microtransactions if players can self-host and modify their own servers

- developers hosting servers is costly

- using a p2p architecture with the "server" running on a random gamers' computer is much more profitable

- but that requires trusting the client, which means

- client-side anti-cheat

Without the live-service lootbox gambling microtransaction bullshit that has infested the gaming industry, none of this would have ever been necessary.

You don't need client-side anticheat if your clan/guild is self-hosting your dedicated servers, you can just ban the obvious cheaters.

[Hikikomori]

How many server side anti cheat solutions is there for ESP and aimbot?

[kuschku]

The question you should be asking is: If you can't tell the difference between a cheater and a regular human player, does it even matter?

Because this question reframes our task, now we only have to measure whether a player is doing something a fair human player couldn't have done.

As we've already have precise mouse movement and timing, and we can calculate what a player would be able to see and/or know at a given moment, we can calculate what they should have been able to do, how fast, and when.

And that's an issue that's common in many other industries outside of gaming, with everyone else having to come up with server-side solutions to the issue.

Reacting to a piece of information that you shouldn't have had access to at a given moment (whether it's insider trading or fog visibility improved by an ESP or a custom monitor LUT) is an easy to measure tell:

http://www.nanex.net/aqck2/4436.html