Cheat Engine

[Neuffexx]

Just recently picked up CE for a small game.
Had no problem finding and manipulating Character Stats once I knew you had to search for them via operation (number*2+1).

And I can even directly find and manipulate inventory items this way.

However, trying to do anything along the lines of scrpting the items to not decrease when used has me stumped.

Found the value of several items, checked to see what accessed them (as nothing was writing to these addresses ever) when I use the items, which were 3 instructions, but only 1 showing up on actual use.

[ParkourPenguin]

It's probably interpreted. Modifying assembly instructions is a bad idea- that changes the interpreter, not the game.
Right click that instruction in the disassembler, select "Find out what addresses this instruction accesses", and play the game for a bit (if you can). Tons of addresses should appear.

Change the bytecode being executed by the interpreter instead. If you don't know what format the bytecode is in, that'll be difficult to reverse engineer from CE. Try a decompiler instead.

[Neuffexx]

[ParkourPenguin]

I'm referring to how the code that the programmer wrote gets executed by your computer. For the most part, there's 3 ways this can happen.

Static compilation is as straightforward as it gets. A compiler transforms code written in some higher-level programming language into machine code (aka assembly) that the computer can run. The problem with this is that a program that was compiled to work on one type of computer usually won't work if you try to run it on another type of computer. This leads to several different builds of an application for each platform it supports- e.g. many applications have separate builds for windows, mac, and linux.

An interpreter tries to solve that issue of platform-dependent builds. Source code written by the programmer is now compiled to an intermediate representation (IR). This IR is designed to be run on any computer via an interpreter. The interpreter is a program that is statically compiled and will execute that IR for the local machine. The problem with this is that there's a lot of overhead: the interpreter must read the IR and translate it to some native machine code operation every single time the code is executed.

Just-In-Time (JIT) compilation tries to solve that issue. Source code gets compiled to IR the same way, but at runtime, the IR doesn't get interpreted: it gets compiled to native machine code. Initially, this has a larger cost than interpretation, but it ends up being significantly faster in the long run since IR code only needs to be compiled once to machine code.

With regards to Cheat Engine, when you find a value and look at what instructions access it, you're hoping to find that the game was either statically compiled or JIT compiled. In those cases, changing such instructions is analogous to changing the source code that the programmer wrote. e.g. changing a `sub` instruction that decreases your money after you buy something to an `add` instruction will increase your money every time you buy something.
If the game was interpreted, however, changing such instructions now changes the way the interpreter executes the code: e.g. changing a `sub` to an `add` could change every subtract operation in the game to an add operation. Obviously, this will have unintended side effects, likely crashing the game.

[Neuffexx]