Transparency Glitch

The Transparency Glitch is a glitch that occurs exclusively in Microsoft's version of Chip's Challenge, when Chip steps on a space occupied by two transparent tiles, meaning any combination of two monsters, boots or keys. A monster stepping on any combination of two transparent tiles, however, will merely erase the lower layer of the grid, or kill Chip if he is on the top of the grid.

Cause

When a monster tries to step on a double-transparent tile, nothing happens because the lower layer is erased normally and monsters do not collect items. When a monster steps on Chip over a transparent tile, Chip is simply killed as normal since this is the first thing that is processed by Chip's Challenge, and again because monsters do not collect items. However, when Chip tries to step on a monster with a non-chip item underneath it, the glitch occurs because Chip's Challenge is programmed to only check the bottom layer of a square if the top layer is transparent. Since this is a recursive process, the stack overflows when the bottom layer is also transparent: the game repeatedly checks the bottom layer until CC crashes.

Blocks

The Transparency Glitch can still occur if a block is on the lower layer, since it acts like a transparent tile when Chip pushes it - even if the intended move of the block was illegal. The first event in pushing a block is the transition from "stationary" to "pushed", and only after Chip arrives at the square does the block change back to "stationary" - thus, the bottom layer is repeatedly checked and the stack overflow occurs before Chip's move is determined as illegal.

Locks

The glitch does not happen if Chip tries to open a lock underneath a monster, since the processes of checking if Chip can legally move onto a lock and its removal from play occur before he moves onto the square - thus, the only process left is Chip being killed.

Possible results

The most common result is a message box showing with the following message:

An error has occured in your application.

If you choose Ignore, you should save your work in a new file.

If you choose Close, your application will terminate.

followed by the buttons Close and Ignore. Clicking either will result in a second message box, which says:

CHIPS caused a General Protection Fault in module CHIPS.EXE at 0007:13FF.

Choose close. CHIPS will close.

Followed by the single button Close. Clicking that button will result in the program closing.

The program may also simply freeze and not respond; in this case, the only option is to manually close it.

A random Death message may be shown, and after the user clicks a button, another message will be shown, saying "Corrupt or inaccessible CHIPS.DAT file", normally seen from the Termination Glitch.

A single box with only an OK option may appear; when the user clicks OK, most of the entire window will turn black and the user has no choice but to close it manually. A special case of this is when two message boxes, a death message and Melinda's offer to skip to the next level, are shown. Then "Corrupt or inaccessible CHIPS.DAT file" appears again, and the program will turn black as above.

Sometimes the playing screen will simply repeatedly flash, in order, cyan, magenta, yellow, and white; the user will then have to close the program manually.

In Jailer, the most famous occurrence, result 1 will happen on the green key and yellow key, result 4 will happen on the red key and result 2 happens on the blue key. Also as a result of the blue-key crash, Chip's Challenge will open from Lesson 1 on its next session.

In one or more of the five events, the toolbox may display a random collection of keys and boots.

Occurrences

CC1 levels where it is possible to enforce the Transparency Glitch are Three Doors, Problems, Hidden Danger, Eeny Miny Moe, Nightmare, Catacombs, Jailer, Miss Direction, Alphabet Soup, Skelzie, Mix Up, and Cake Walk. Note that only a couple of these, notably Mix Up and Jailer, are likely to occur in actual play, but all are technically possible.

In CCLP2, because of the greater number of monsters in general, more levels can trigger the glitch: Naomi's Bug Collection, Bea's Den, A Sample of Things to Come, Block Away!, Chase Race, Lot of Danger, Beware of the Teeth!, Madness II, Bumble Boy, Madd Maze, Crypts of Aganorak, Creative One-Ways, Hard as Rock, Tricks, Paramecia, Blocks 'n Bombs, Miscellaneous, Block Maze, Zartacla, Keep Trying, Trapped, and Key Color are all possible occurrences.

In CCLP3, levels that can trigger this glitch are Motion Blur, Zelgon's Lair, Air Pocket, Coal Mine, Niche, Billiards, Freezer, The Ghosts at the Massingham Mansion, Magic Trick, Stress Fracture, Manic Depression, Water Trap, Beat the Heat, Everybody Get Dangerous, Four by Four, Think Tank, You Can't Teach an Old Frog New Tricks, and Diabolical

The Transparency Glitch does not exist in Tile World. Should Chip step on a monster with a key or boot under it, he will merely die as usual; should he step on combinations of keys and boots, he will collect the top and reveal the bottom as with any other combination of two tiles. An easy way to eliminate the glitch from occurring altogether in the MS ruleset as well is to patch CHIPS.exe with CCpatch by ccexplore.

The Transparency Glitch also does not exist in CC2.

Sources

Not All The Bugs Are Yellow David Stolp explains the finer points