Sly 1:Anticrack

Anticrack is a feature of designed to prevent modifying the game. It performs periodic integrity checks using a checksum to ensure that the code has not been altered. If a check fails, one of four penalties is activated.

Firewall
If the integrity check in the function at  fails, the flag at   is set, which activates the firewall penalty. This penalty spawns an invisible wall of fire in the level Into the Machine once the final segment of the map has been loaded for 1 minute and 27 seconds.

Once the firewall is active it sets a scene variable which persists on the save file, making it permanent once you save the game. This means the firewall will be active even if anticrack is disabled on the next boot.

Anti-grab
If the check in the function at  fails, the flag at   is set, which activates anti-grab. This penalty is activated in two stages:
 * After 30 seconds of in-game time, jumping and pressing circle to climb will fail intermittently.
 * After 2 minutes, climbing is disabled altogether.

Vehicles
If the check in the function at  fails, the flag at   is set, which activates the vehicles penalty. This check occurs after an FMV is played for 3 seconds. Since the game starts with an FMV of the Sucker Punch logo, this check is triggered when the game is booted. This penalty has two effects.


 * 1) The van's acceleration will be capped at 40%. The function , which is called every frame, is supposed to set the van's velocity target value,  , to some value calculated by the physics engine. However, if the vehicle penalty is active,   is multiplied by 0.4. This speed limit makes the race levels impossible to win.
 * 2) The blaster's cannon will be fully disabled on the hover blaster levels.

Collectibles
If the check in the function at  fails, the flat at   is set, which activates the collectibles penalty. This penalty has two effects.


 * 1) The key count on the world state will not increase when collecting a key. Since you need a certain number of keys to reach some areas, this effectively halts all progress.
 * 2) Clue bottles are affected after 2 minutes and 55 seconds of in-game time.
 * 3) * Upon dying or loading a level, each clue bottle you previously collected will have a 20% chance to be un-collected. This is accomplished by randomly selecting 20% of the  flags from the current level state and setting them to 0 when the level is loaded. For each bit that is unset, the   is decreased by 1.
 * 4) * Each clue bottle in the level will have a 20% chance to turn invisible, making it practically impossible to find them all. This is accomplished by iterating over each clue bottle in the level and turning it invisible.

History
The earliest known reference to anticrack was on Oct 6, 2002, less than a month after the game's release. A user posted on the neoseeker.com forums about "technical problems" with the game, describing in detail each of the measures outlined above. According to one user in the comments, Sucker Punch replied to their email saying that "the problem is due to megamemory or gameshark, where it requires a preboot disc. Using those somehow corrupts the gameplay".

For the next two decades, several guides and forum posts would continue to pop up, each time attributing the issues to technical glitches caused by using cheat devices like GameShark or Megamemory.

Gamespot user Dark_Shadow_X emailed Sucker Punch about the issues, and they responded as follows: The problem surfaces when the user has some non-authorized memory cards, or some utilities like the Gameshark installed. Here's what we do know:

1. The problem manifests itself as an inability to use the circle button to grab ladders, hooks, pipes, etc.  In addition, you seem to lose a key from your total--meaning you won't be able to open a particular lock when you should be able to. Most often these problems will be seen in the first level of Raleigh's World, and people have complained they cannot grab the hook before going over the gate, or that they cannot open the gate at the end of the level.

2. In all cases we've investigated thus far, removing the additional accessory has returned the game to normal. Note that three Sly Cooper save games fit into 59K of memory, so the save game will consume just a tiny fraction of any PS2 memory card.

In 2019, Meos discovered these issues are not technical glitches, but in fact deliberate anti-cheat measures programmed into the game. He posted a video showcase outlining exactly how each measure works and what triggers them. snZ7xQI-B8k