AvalancheMaster... OK Good Find.
I wonder what other things could be a simple fix handled with a hex editor.
...depends on IF Hard Coded or not.
I've tried adding eras and terrain types (or deleting as well) - that's definitely hardcoded. Eras stay 4, terrain types stay 13 (or was it 14?). If I delete one, the game crashes, and the editor won't load the files.
What's more thrilling, and what I've already discussed with Oz, is the possibility for a script language for events within a Civ3 game. Now, I do need to check the hex of the save files, but if they are similar to the BIQs, I don't see why this wouldn't be possible.
Such a script language wouldn't be all-powerful - we will still be limited to 5 advisors, 4 eras, fixed number of worker jobs, etc., etc.
However, it will still allow for a splendid flexibility. Think of recreating historical events - founding cities on an exact date at an exact location. Also, it can be a way to modify what roads, irrigation and mines do (e.g. - mines that provide commerce, irrigation that provides different amount of food for different civs). It will allow for a great flexibility.
Again, it will not make everything possible, in fact, here's a list of some things that cannot be changed:
1) Any part of interface
2) How railroads behave (excluding the extra bonus they give to irrigated/mined tiles)
3) AI strategies. You can flex them a wee, but that's all.
4) Maximum cities
5) Biggest workable area around a settlement
6) Number of worker actions
7) Number of eras
Still, here are some things I think will be possible:
1) Tech requirements for Build Colony and Build City (though they won't show in the Pedia/Scientific Advisor screen)
2) What bonuses do irrigation, road and mines give
3) Rivers move across the map while time passes
4) Dynamic terrain, hellyeah!
5) Dynamic governments (becoming less/more corrupt with time; with less/more scientific output).
6) Recreate historical events
Now, keep in mind that the changes can only occur one turn a time (that means, you won't have a change in the middle of your turn). Still, I do believe it is possible, and I do believe it will be extremely helpful.
Now, I am no programmer myself, but I do guess that such a scripting tool will be possible only if save files can be edited and if the game reloads a temporary cache between turns. The most crucial part is actually what the game does between the turns. If we're able to find out what's happening between turns, such a tool is entirely plausible.