Cheat Engine

[aeridus]

How do I hack a game so that I can walk through walls? The game I'm trying to hack is Arc The Lad 2, on epsxe... simple 2d map style, shouldn't be hard...

I can hack just about anything else though, but then stats and hp/mp are easy to hack.

I'm guessing that I'm looking for something in the form of xxxx, where each binary digit represents whether a direction is walk-thru able or not.

Edit: Well, so far I managed to make it so the character is permanently sashaying when she moves. XD Found the sprite values apparently. Also, I know where the x+y coordiantes for the character are but fiddling with them does nothing. Finding out what accesses the coordinates and then screwing up that makes the game go bizarre.

Edit#2: Seems that I found the byte... it's always 0 when there's nothing in front of me and 8 when there's a wall... now how do I fix it so that the addresses that read from it always read 0? It's a bit fickle, and I don't fully understand the debuger yet.

[aeridus]

Gah, it's so fickle, I'm not sure exactly what i should replace the code with and how.

Here's the address that writes to the location:
06350434 - 89 1c 08 - mov [eax+ecx],ebx

And these four (four directions I presume) read from the location:
0636668f - 8b 00 - mov eax,[eax]
063668c2 - 8b 00 - mov eax,[eax]
06367f09 - 8b 00 - mov eax,[eax]
063925c3 - 8b 00 - mov eax,[eax]

The location itself is at:
ePSXe.exe+3B6C8C (007B6C8C on my computer)

And the value is 0 if the direction you face has no obstacles, 8 if otherwise.

How do I fix it at 0, considering the regular "lock in place" command doesn't help with the walk through walls situation?

I've tried replacing either the write-to or read-from commands with nops but that just crashes things, which makes sense as they are a bit intricate... but what should I replace them with and how? I've done a little assembly before but this fazes me.

Edit: I tried the code-cave method I read about, but it just causes crashing. Maybe I have the wrong value after all, but it sure is suspicious... I haven't found anything else as consistent as it is.

[aeridus]

Hmm, I did some more thorough searching and found 5 values that seem to change depending on whether the wall is there or not... all seem to be adjusted by that singular piece of code. So obviously trying to replace that code would result in chaos.


status: didn't encounter wall, encountered wall
value 1: 0, 8
value 2: 0, 4
value 4: 60, 228
value 5: 193, 191

status: just went left, just went right, just encountered wall/went down, just went up
value 3: 2, 6, 0, 4

Keep in mind that all values are 1 byte in size.

Has anybody seen anything similar to this in wall values of other games?

Edit: One last value found, for up and down, is:

status: just went up, just went down, just encountered wall/went left/went right
value 6: 252, 4, 0

252 is equivalent to -4, I know that much... odd that the number scheme should be slightly different for up down compared to left right.

All values found are right next to each other, so most likely there's some interaction at play. 007B6C8C-007B6C9D is the range, fairly small.

If anyone could at least give me some insight into the solution of this problem, I would greatly appreciate it; this unreachable treasure chest is driving me nuts and I can't find a single walkthrough that has a clue how to get it... I've searched every nook and cranny for hidden switches and doors and the like.

[aeridus]

Bah, I finally found out how to get to the chest, the false wall was a heck of a thing to find.