Looking for Players
WARNING: The new AI cannot be used in LAN, playing with the AI in LAN is only possible with the MMH55-Utility.exe file!
First of all, HOMM5 is a game that is 'hard to mod' and can only be modified using script extensions. Scripts are however disabled by default in Hotseat and LAN. (if you only play the game in singleplayer, you won't have this issue). Therefore ARMG maps without scripts activated are completely broken in multiplayer (Hotseat and LAN). All default H5 maps have script activated as well as all the maps that came with MMH5.5, so you don’t need to worry about those.
The easiest way to activate scripts on a newly generated map is by using the reanimation patcher, you can find the shortcut to this tool in your start menu after installation, the operation is self-explanatory: just press patch maps, you can select multiple maps and process them at once.
You can also activate scripts with the latest mapmixer utility by activating the option 'make LAN/Hotseat compatible.'
Lastly, this describes the manual procedure for activating scripts on a single map if you like to work in the editor:
1. Open map with the Map Editor ("File" -> "Open")
2. Search for "MapScript" on the left panel (If you don't see the panel,
then "View" -> "Map Properties Tree")
3. Click "New" button next to "MapScript"
4. Type something to the "Name" (for example: MapScript)
5. Click "OK"
6. Save map ("File" -> "Save")
7. Close Map Editor
Choosing a global network
Tunngle has proven to be very stable and reliable, Gameranger also works well and is currently the most popular platform in our discord community, but you have to use a trick, rename the H5_Game.exe file to H5_Game_original and rename the MMH55.exe file (or MMH55_64.exe) to H5_Game.exe. Some people have reported issues with Hamachi, but since there are so many possible different setups (hardware, OS etc) I cannot say with 100% certainty it is really bad.
Preventing Synchronization Issues
The original multiplayer software for HOMM5 is sensitive to synchronization issues, generally you want the game folders (data folder, maps folder and usermods folder) of both players as much as possible to be CLONES of each other. Here are some tips to prevent issues:
1. SAME VERSIONS - All players must have the same version of the game and MODs. Unless this requirement is met you will get checksum error while trying to join a game.
2. INDEX.BIN and RMGTemp - When generating a map it is very common that a file called "INDEX.BIN" or folder "RMGTemp" will appear in heroes folder/DATA. The file/folder is corrupt and interfere with the game synchronization. It is advisable to check for it (and delete it if exists) each time you start/join a game. You don't need to backup these files, they already exist in the pak files.
3. SINGLE PLAYER CUSTOM SAVES - All players need to have their single player custom game saves removed before joining/creating a multiplayer game. Unless this is done a checksum error will appear upon joining a game. To remove custom saves go to "Single player -> Custom game -> Load game" and delete everything there! If there are too many you can also lookup the folder in windows explorer.
4. SAME EXEs - All participants should use the same EXE versions of the game. For example Might and magic 5.5 comes with 2 exe versions - 32 and 64 bits.
5. SAME MAP - Unless participants play default map, additional maps that you place in MAPS folder have to exist in MAPS folder of the other players too. Otherwise they wont be able to join!
It is also advisable to put only the map file you are currently using and keep the folder clean. Since H55 has demo maps I recommend both players keeping or deleting them all just to be 100% sure.
6. Eight skills - Whenever you start a new LAN game using the 8th skills option you must follow these steps otherwise desync is very likely to happen midgame and turns would not be passed. Also some of the players (that do not have 8th skills on) may have some of their main heroes skills changed/removed when loading save game.
a) Before creating/joining a new or saved game all participants must activate the 8th skills by going Multiplayer -> Hot Seat -> Standard Game and mark the 8th skills option as shown here (Here is how it looks unmarked ).
b) Create/Join the game and play.
c) 8th skills option should be ON before joining a saved game that has been started as such. If one or some of the players join without the option ON game.
Note - 8th skills option is automatically turned off every time heroes V application is closed. The save game do not include a note on how many skills the game started with so check it everytime when loading :).