Anticheat Update Tracking

Forgive my ignorance, but why don’t game developers put more effort into limiting the amount of data accessible to the client (restricting it only to what’s reasonably necessary)? For example, couldn’t more movement physics be validated or handled server side? Cheats might still be able to read some data from the game process, but ideally, they’d be limited to issuing inputs like any other player, based only on the same visible output everyone sees. Is it cost? Does this model just not align with how the client/server split looks in games?

That's exactly what's being done, but you do not want everything server side over a network delay that is almost always more than the time between frames. Only server side physics would mean a lot of visual jank. It's now usually a model where the client and server make the calculation and the server "rolls back" the client of they do not match.

Data is being limited though, like not sending opponent location data unless the client can see them

> Data is being limited though, like not sending opponent location data unless the client can see them

So far as AAA games go this is pretty rare in practice. I guess there could be some problems to solve, e.g. you'd need to be conservative because a player could appear around a corner between server ticks, or the fact that RTS games usually operate by running a shared simulation[1].

[1]: https://www.gamedeveloper.com/programming/1500-archers-on-a-...