Map protection
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The term Map protection refers to the process of corrupting custom StarCraft and Warcraft III maps in order to render them unreadable by the official map editors included with each game (StarEdit and the Warcraft III World Editor, respectively).
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[edit] Overview
Whereas with computer software and media there is DRM, "map protection" is an act of corrupting a map's internal archive by the author of the Warcraft 3 map in order to protect his/her interests. Map protection is used mainly to protect the map from having its data stolen or modified (such as to sneak in an unfair advantage), but also to keep credit for the map where it belongs.
Unlike DRM, however, there is no legal precedent for a map author taking legal action against those who edit his or her work. It is strictly a community-enforced policy to respect the author's wishes on such matters. Additionally, being that Blizzard never explicitly programmed support for map protection into the game, all attempts at map protection are invariably attempts at exploiting how the map editor and game program behave when encountering unexpected conditions when reading a map. This makes all attempts at map protection especially limited in scope, in comparison to software protection for example.
Furthermore, should the author abandon his/her work or respond slowly to a game update that breaks the map, the fanbase of that map must play it as-is, in its broken or unfinished state. The exception being if a player decides to deprotect the map themselves (and succeeds) in order to further development of the game. Some players do not mind this method, but there is often negative reactions to such acts.
[edit] Protection methods in Warcraft III
Warcraft III maps are saved in the MPQ format, which means that every map is effectively a collection of other files identified by a path. Many of the files included in a map are for the campaign editor's convenience only. The basis of most map protectors is removing or corrupting files that only the editor needs in order to access the map.
[edit] Map script and convenience files
All maps include a file named war3map.j. It is known as the map script file. This file includes a lot of map-essential information (such as custom triggers, camera positions, ect.) However, due to the nature of scripting languages (such as the one used by war3map.j, Jass), it is difficult to get the important data out of a script and into a suitable format for humans to edit. Because of that, the World Editor adds several convenience files in a simple format to avoid having to do it the hard way. These files are war3map.w3c, war3map.w3r, war3map.w3s, war3map.wtg and war3map.wct.
If one or more of these files (especially the warmap.j file) are damaged or removed, the World Editor will either refuse to open the map or open the map with the appropriate data missing. This is a common, but outdated protection method.
Utilities exist that make attempts to restore corrupted files in order to make the maps readable in the World Editor. These programs are most often used by people who are unable to work through the file corruptions themselves when attempting to either edit the map to their advantage or to learn how it works.
[edit] Map script obfuscation
The map script file is easy, as files go, to read in a text editor such as Windows Notepad. The World Editor strives to make it as close to human-readable as possible when the map is saved. This means that if a user knows Jass, they can open the map script file and discover any secrets or easter eggs that may have been hidden by means of other protection methods.
Obfuscation is the process of changing a script file so it is harder for a human to read but identical from an interpreter's perspective. However, some obfuscation methods are incompatible with some maps. Obfuscation is commonly used in conjunction with removing the editor's convenience files.
[edit] Map script hiding
Due to the specifics of the Mo'PaQ format used by Warcraft III to store maps, to open a file included in a map you must know the path of the file you want. A similar protection method to map script obfuscation is changing the path of the war3map.j file to Scripts\war3map.j. This path is not known by some MPQ editors, which makes the map script effectively unaccessible unless the user knows how this protection method works. The game knows of this path, however, and will be able to load the map script normally.
[edit] Corruption when saved
An alternate method of map protection allows the map to be opened normally in the World Editor, but will corrupt the map when it is saved, making it difficult to alter and re-distribute the map, but lets the map be inspected and used for learning purposes. There are many ways of accomplishing this:
[edit] External links
[edit] Documentation
- War3 File Download Area--A website that hosts various Warcraft-related files, as well as information on map protection.
- Warcraft III Map Unprotection--A website hosting information on the various methods of protection and how to remove them.
