Cheat Engine

[BenH]

First off, I already know how to do both of these steps. I'm just having trouble understanding what actually is going on.

Step 5: Code Finder involves making a table for a variable that changes its location in memory, e.g. every time the game is started. I found the code that writes to the address that the value is stored, and I replaced the code with nothing, lighting up the next button. However, to test the table I restarted the tutorial and reopened the tutorial process, but my table no longer works. The value changes again and the next button doesn't light up until I repeat the steps I already did. Why is this happening? I thought I removed the code that changed the value so that shouldn't be able to happen. Moreover, I thought the whole point of this step was to make it so we don't have to go through the steps to find the value's location every time we open the game. But evidently, we do.

Step 6 is the one level pointer tutorial. On my understanding our goal is to find the pointer to the value we are interested in, because this pointer never changes. Presumably such a pointer must exist because the game probably needs it itself. According to this tutorial you're supposed to find the value and then check what writes to that address. Getting more info gives us a pointer whose value is the address of the value we are interested in. My question is, what is the point of that? We already know the address of the value of interest. We can just search it in hex directly without checking what writes via the "what access this address" method. Secondly, I don't get how checking what writes to the address of interest (e.g. health points or whatever) is related to the pointer to that address in the first place. The pointer doesn't write to the address, it just stores the address in memory, so why would I be interested in what writes to the address?

Thanks,
Ben

[Rydian]

1a - The removal is temporary, it modifies the program/game in RAM. Once you close and restart the tutorial/game, the modification no longer exists (since it's starting up clean) so you'd have to do it again.

1b - For instances where the code changes, you'll want to use the AOB injection template which will scan for the right code to modify (instead of blindly modifying code at a specific address).

http://forum.cheatengine.org/viewtopic.php?t=570083
This thread has a little more info on why and all that jazz.


2a - "Presumably such a pointer must exist because the game probably needs it itself." In the case of the tutorial, yes. However note that a lot of games are coming out nowadays in managed languages or with internal scripting engines so it doesn't always apply.

2b - It wants you to use accesses, not writes. The first goal is to get the base value of the structure that your target value is in, I believe. In this example the base and target happen to be the same thing because the structure starts with what we want. Note that the opcodes involved just say [eax], whereas in many games it'll be [eax+34] or something so you'd need to either do this or some manual (calculator) hex math to find the start of the structure.