Backward compatibility of MP Eras

[White_Drag0n]

Title. Is it possible to code a MP Era in such a way, that if host uses a different version than the rest of participants, the game is loaded on his version for all players? I know that something like this is used in EoHS, and wonder is there's any quick way of doing it for simpler eras. Perhaps some WML Wizards from this site might give a helping hand? Or is it more a lua thing to do?

[Ravana]

EoHS is designed to work no matter if participants even have it loaded, which is why it is not affected by them having different version. Also, EoHS is not really era, that name is just remaining from era of no modifications.

[Sapient]

It's possible to embed Unit Type WML into the Scenario WML (perhaps inside a [set_variables]), using macros, however this would obviously increase the size of Scenario WML.

This variable could then be used to overwrite things like attacks, moves, defenses.

However some things would be difficult to do correctly, such as playing nicely with other modifications in the scenario.

Other things would be impossible, like introducing new unit types.

[gfgtdf]

In wesnoth 1.13 the game engine can autoamtically downaload the latest version of an addon from the server if it detects that your addon version is incmpatible with the addon version of the host. So if you want to start writing an mp era now it might be uneeseary to think too much about this.