This can be done modding?

[av29 2]

And it would be difficult?

1- Adding new types of zoning and density

2- Adding new building rewards that are mutually exclusive (not only in pairs, but in trios and more...). I know that some kind of exclusivity can be done with them, i.e the major statues, but IRC they was some kind of bug that allowed you to bypass the restriction and place both male and female gender.

If this is possible, opens up to a lot of possibilities (just thinking about it, it's not that actually will do it or ask for somebody to...). Basically I'm thinking with a "city specialization mod", tying the building rewards, to some kind of zones and/or densities.

There's some mod in this direction, if this is possible (also if it is only the 2 option, with the normal zones)?

[rsc204 21,866]

Adding new zoning types would require modifying the games main code (.exe) to work, something which is not very likely to be realised.

Building rewards are generally controlled via LUA scripts, which have been used in the manner you outline, most prominently for the BSC Reward Chains used in much BSC content. Placing both statues for example is enabled by a cheat code, using CTRL + X to bring up a entry box and typing "You Don't Deserve It" will unlock all locked buildings until you next open a city. It may require an addon, the SC4 ExtraCheats.dll file to work however: