Victoria 3 – Tips for Modders

Some tips that no modding documents will tell you.

Modders Tips

All credit goes to CommonAnts!

1. One should not show too long tooltips, or the game will crash. Use hidden_trigger and hidden_effect instead. This is also true for EU, HOI, CK, Stellaris and IR.
2. One must check the existence of scopes in Vic3 to avoid errors. Use trigger_if = { limit = { exists = c:XXX } this = c:XXX } trigger_else = { hidden_trigger = { always = no } }, rather than this = c:XXX.
3. 【I am not sure of this so just ignore this now.】 One have to modify vanilla files in state_regions and common/histroy, rather than adding new files. These files are dual loaded, if one modifies them with new file name while rewriting vanilla content. Which means the vanilla state region/history and the modified one would be loaded together. Once potential resources in that region become discovered, it would be discovered twice, and all resources buildings built in that state region are destroyed. Population and buildings would be added twice. And if you change history of states owners so, the state population and buildings are never loaded.
4. Some gfx files are invalid in mods, such as land_mask.dds and the setting of gradient border. They must be modified in the origin vanilla files.
5. Limit seems to be short-circuit evaluated, but AND/OR/NOR/NAND are not. Therefore, limit = { exists = c:XXX this = c:XXX } is ok, but AND = { exists = c:XXX this = c:XXX } is not.
6. Effect statements in on_actions seems to be incompatible with other effect in the same on_action. Use events instead.
7. Global variables must be permanent, while normal variables can be timed and used like a timed flag.
8. Non-exist scopes cannot be removed from lists with remove statements, one have to make a new list with other items added and clear the old list.