sometimes you don't need to decrypt/manually send packets yourself if you can get the engine to do it.
Its hard to help because im unfamiliar with the game... but if you can get an inventory of some sort, drop/pickup the same item and search for 0/1 until you find the address, in cheat engine put a break-point on the instruction and look at all the registers. then switch the item and compare the registers for differences, this could be the item offset/ID. next time you go to pickup an item, force the information in the register to be the expensive item.
If you are getting WPE errors then maybe you aren't using it correctly... try to duplicate something like moving to a certain location or something.
the value for speed is probably held in a memory address somewhere depending on the vehicle you are in. search and set.
Good luck and im curious to hear the solution you come up with.
I've only just learned how breakpoints work in general
. I don't even know what you mean by the registers offset/ID. I can change values and things, but every time I interact with the server in some capacity they are just reset.
The game has to build the packet .. ( hmmm ) .. then encrypt it.
get to work.
I know that much from tutorials, but I have no idea about how to modify the packet before it is encrypted, or even where to start. I'm still new to Ollydbg and Assembly is like an alien language to me.
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I think I'll try just mastering CE or something and attempting to hack other, simpler games until I know what is happening. I don't even know C, C++, and don't have the time to really pick them up with full summer courses and a job. The only way I'd ever get close is for someone to handhold me through the entire process.