Latest update:

Yes, it is absolutely possible to play Caesar III with a "no-fire" cheat & forget about burning cities! However, this requires:
  1. using an alternate Caesar III implementation. In this HOWTO I use Augustus (it's a free software), but you may use Julius as well.
  2. patching such an implementation & rebuilding it from source. It is not as complicated as it sounds.

The steps below are for Windows 10/22h2, but they also should work on Windows 7. Run everything under a regular, non-administrative account.

Installing Augustus

Before we begin the patching procedure, make sure you can run the latest, unmodified Augustus.

Install 2 command line packages from scoop. (If you use Windows, but don't use scoop, you're missing out.) 

scoop install unzip innoextract

Download to $env:USERPROFILE/Downloads/ directory:

  1. an .iso of the GOG version of Caesar III; it costs just a couple of bucks;
  2. Augustus itself. Look for augustus-A.B.C-windows.zip file.

Unpack everything to, say, d:/games/augustus/:

mkdir -p d:/games/augustus
cd $$
unzip $env:USERPROFILE/Downloads/augustus-3.2.0-windows.zip
innoextract -m $env:USERPROFILE/Downloads/setup_caesar3_2.0.0.9.exe

(innoextract util will dump everything into "app" directory.)

The resulting directory should look like:

ls | ft mode,name

Mode   Name
----   ----
d----- app
d----- assets
da---- manual
da---- maps
-a---- augustus.exe
-a---- SDL2.dll
-a---- SDL2_mixer.dll

Run the game:

./augustus app

Your savefiles will be in the app directory.

Optionally (but highly recommended), create a shortcut on the Desktop:

$w = New-Object -comObject WScript.Shell
$lnk = $w.CreateShortcut("$env:USERPROFILE/Desktop/Augustus.lnk")
$lnk.TargetPath = "d:/games/augustus/augustus.exe"
$lnk.Arguments = "app"
$lnk.WorkingDirectory = "d:/games/augustus"
$lnk.Save()

Patching the game

Here is an already patched version: a ZIP archive with 3 files: augustus.exe, SDL2.dll, SDL2_mixer.dll. Unpack it to d:/games/augustus/.

If you want to do it yourself, read on.

Install MinGW-w64 & CMake

scoop install mingw cmake

Restart the terminal window(s), then check both the compiler & cmake:

gcc --version

gcc.exe (x86_64-posix-seh-rev2, Built by MinGW-W64 project) 12.2.0
Copyright (C) 2022 Free Software Foundation, Inc.
This is free software; see the source for copying conditions.  There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

cmake --version

cmake version 3.26.1
CMake suite maintained and supported by Kitware (kitware.com/cmake).

Fetch Augustus source code & dependencies

Get Augustus:

mkdir -p $env:USERPROFILE/Documents/forks
cd $env:USERPROFILE/Documents/forks
curl.exe -LOJ https://github.com/Keriew/augustus/archive/refs/heads/master.zip
unzip -q augustus-master.zip

Get 2 dependencies:

  1. SDL2: look for SDL2-devel-A.B.C-mingw.tar.gz file.
  2. SDL_mixer: look for SDL2_mixer-devel-A.B.C-mingw.zip file.

Unpack:

cd augustus-master/ext/SDL2
unzip -q $env:USERPROFILE/Downloads/SDL2-devel-2.26.4-mingw.zip
unzip -q $env:USERPROFILE/Downloads/SDL2_mixer-devel-2.6.3-mingw.zip

I.e., augustus-master/ext/SDL2 directory should look like:

ls | ft mode,name

Mode   Name
----   ----
d----- SDL2-2.26.4
d----- SDL2_mixer-2.6.3
-a---- Android.mk

Compile, test, patch, recompile

Now, first compile Augustus without any patching: 
cd $env:USERPROFILE/Documents/forks/augustus-master
mkdir build
cd $$
cmake .. -G "MinGW Makefiles"
make

Second, copy obtained augustus.exe to d:/games/augustus/, overriding the previous .exe file. Do the same for the both SDL2 dependencies: 

cp augustus.exe d:/games/augustus/
cp ..\ext\SDL2\SDL2-*\x86_64-w64-mingw32\bin\SDL2.dll d:/games/augustus/
cp ..\ext\SDL2\SDL2_mixer-*\x86_64-w64-mingw32\bin\SDL2_mixer.dll d:/games/augustus/

Third, run Augustus. Do not proceed further unless there are no errors.

Fourth, download the patch, & apply it: 

scoop install busybox-lean
cd $env:USERPROFILE/Documents/forks/augustus-master
cat $env:USERPROFILE/Downloads/augustus-no-fire.patch.txt | busybox patch -p1

If there were no errors, recompile:

cd build
make
cp augustus.exe d:/games/augustus/

Run the game! It will still complain that a building has collapsed, but in reality nothing will collapse. To ignore annoying popups, select "Show new message as alerts instead of popups" checkbox in Options.

Бонус: локалізація

На жаль, української локалізації не існує, тому я рекомендую грати в оригінальну, американську версію. Одначе, у цю іграшку хотіла пограти моя мама, а англійської вона не знає.

Є 2 варіянти з російською: (а) переклад лише інтерфейсу та повідомлень, (б) додатково переклад саундтреків. Останні є, як на мене, неймовірно огидні і були зроблені, я вибачаюсь, конторою 1С на початку 2000х.

Для варіянту А завантажте "Рашн" патч, потім: 

cd d:/games/augustus/app
mkdir ru
cd ru
unzip $env:USERPROFILE/Downloads/caesar3_update_russian.zip
ls | ft mode,name

Mode   Name
----   ----
-a---- c3.emp
-a---- c3.rus
-a---- c32.emp
-a---- C3_fonts.555
-a---- C3_fonts.sg2
-a---- c3_mm.rus
-a---- patch_readme.txt
-a---- readmeupdate1.1.doc
-a---- readmeupdate1.1.txt

(Жодних інструкції з файлів .txt/.doc виконувати не треба—вони стосуються геть іншого випадку.)

Запустіть гру, в Options виберіть "ru" у якості іншої мови і натисніть кнопку Apply. Результат має виглядати так:

settings dialog

Для варіянту Б, якщо ви є мазохіста, заторентіть .iso файла, який є схожий на те, що колись розповсюджувала 1С. Змонтуйте його, нічого звідти не запускайте заради бога, а просто скопіюйте директорії smk та wavs до d:/games/augustus/app/. Відмонтуйте той .iso та видаліть його.