What exactly extends trade routes?

[phamdinhnam02]

I've explored all capitals thinking my trade routes would reach, but they don't. What exactly extends trade routes?

 

[SupremacyKing2]

Nothing extends trade routes, they have infinite range but they cannot pass through tiles with miasma or unexplored tiles. In other words, a trade route will only be available if the game can trace a path through explored tiles (no fog of war) through non-miasma tiles from the sender to the receiver. This will make it more difficult to make trade routes with distant AI cities in the beginning.

 

[KrikkitTwo]

(note; the trade routes also cannot go through mountains/canyons/ice, etc.)

 

[Primacide]

Just an FYI: if you research alien hybridization (I believe), it gives your units immunity to miasma. This applies to your trade units as well. It's on the harmony path, but isn't particularly early, so you'd have to wait a bit to capitalize on it, but it is situationally useful.

 

[Miravlix]

Harmony, I think level 2, make trade units ignore miasma.

 

[NukeAJS]

Also, you must reveal the tile a city is on while it's an actual city. This means two things:

1. Revealing the tile while it's an outpost will not allow you to send trade routes (or spies) to that city until you send a unit after it has matured to a city.

2. Revealing tiles, then having a rival plop an outpost down in the fog of war won't work either. You'll have to send a unit.

Lastly, all players' capital tiles are revealed to you as soon as you meet them. You'll still have to reveal all the tiles between you and them to send a trade mission that way, though.