Originally posted by Saintmagician on the .com.au forums;
http://forum.travian.com.au/showthread.php?t=7088


Expansion Slots

The purpose of this guide is to explain exactly how village expansions work. Something that seems to confuse a lot of people. In all fairness this is complicated and the official FAQ really does not document it well. Given the frequency that questions about this come up, and the frequency that otherwise experienced players seem to answer them wrongly... I decided to write this.

1. Unlocking and using expansion slots

Unlocking an expansion slot involves building a residence or palace and then producing settlers/chiefs. The required levels are:
Residence lv10 or Palace lv10 - unlocks the first slot
Residence lv20 or Palace lv15 - unlocks the second slot
Palace lv20 - unlocks the third slot

Using an expansion slot involves turning settlers or chiefs into an actual new village. This requires you to have enough CP.

Yes, the second stage depends on the first stage. However the requirements for the two stages are completely independent.

  • You need enough CP to use settlers/chiefs (using an expansion slot), however you do not need enough CP to be able to produce settlers/chiefs (unlocking an expansion slot)
  • Similarly, you need residence/palace levels to produce settlers/chiefs (unlocking an expansion slot), but you do not need them to actually use the settlers/chiefs (using an expansion slot)


2. Scope of expansion slots and CP
CP is account wide, and not attached to villages. Hence if you gain a new village, the amount of CP required for another village increases. But if you lose a village, the amount of CP required for the next village will in fact drop.

Example: I have 6 villages, I need to reach 99000CP before I can gain a 7th village. However if I get a village destroyed or chiefed (and fall back to having only 5 villages), then I will only need 65000CP to gain my next village. Since CP never decreases, it means if you lose villages then you are instantly able to settle/chief new ones.

Expansion slots, when used, are linked to villages and not accounts. What this means is that if VilA founds VilB, then VilB occupies an expansion slot of VilA.

If VilA changes ownership (i.e. is chiefed), VilB will still occupy VilA's expansion slot. The fact that a different account now owns the village does not change the expansion slots.

3. Expansion slots are transferable
If VilA founds VilB, but VilC chiefs VilB. What will happen is that VilB will be 'transfered' to VilC.

This means VilB will now occupy an expansion slot of VilC, and VilA will have one of its slots free to use again.

Of course, in order to use the free expansion slot at VilA, you may need to unlock it again (i.e. build residence/palace to an appropriate level and rebuild settlers/chiefs).

Implications
Moving Palace
Firstly, you do not need residences or palaces for chiefs to work. Hence it's entirely possible to use a palace to build 3 chiefs, or to build 2 chiefs more cheaply (lv15 palace is cheaper than a lv20 residence), then knock down the palace so it can be built elsewhere. Those chiefs will still be able to lower loyalty and will still be able to chief a village.

Self-chiefing
Secondly, since expansion slots are transferable, you can self chief your villages. For example:
VilA founds VilB (hammer)
VilB (hammer) founds VilC
VilC founds VilD
VilD techs chiefs and chiefs VilC

This is possible, and will leave expansion slots looking like this:
VilA - slot 1 occupied by VilB
VilB - all slots free
VilC - slot 1 occupied by VilD
VilD - slot 1 occupied by VilC

In this way, VilB will have 3 slots free for three chiefs.

Of course, you need to pay the cost of teching and using 1 chief from VilD. In addition, VilC will lose all troops, wall and all research/upgrades. So it's expensive...why would you do this?

Well looking at the above example, say if you had VilA and VilB, and you know you wanted three chiefs from VilB. How would you settle your third village? Your two alternatives are:
1. Get residence to lv20 at VilA (spawn village) to settle the third village, hence leaving VilB's slots free
2. Use a slot from VilB, and then self-chief later down the track to free it again.
Method 2 is still probably more expensive. But...method 1 involves pushing a level 20 residence early in the game, where it is very difficult and will set you back a lot. Where as self-chiefing is something you can do later, when the cost of teching and using a chief is really not very significant.

In other words, you can self-chief later down the track, to shuffle expansion slots around, when chiefs really aren't expensive. And avoid any level 20 residences early on in the game, when they are VERY costly.

NOTE about CP: You still need enough CP to be able to self chief. For example, if you have 6 villages, you need to have 99000CP before you can self chief. However, after you self chief...you still have 6 villages. Hence you still need only 99000CP to gain a 7th village.

NOTE about population drops: If you chief from a lower ranked player, all fields/buildings will lose 1 level (usually approximated to a -100 drop in population). This does not happen if you chief from a higher ranked player, or if you chief from yourself (the game considers it as chiefing from a same ranked player).

Using lv15 Palaces
This is an alternative way to organizing your expansion slots early game.

Instead of using the first slot to gain new villages, then self-chiefing to organize your slots later. You use a lv15 palace to unlock a second slot cheaply (well, more cheaply than a lv20 residence). For example:

VilA (spawn) founds VilB (capital)
VilB (capital) founds VilC (hammer)
VilB (capital) founds VilD
VilD founds VilE

So VilB would be using a lv15 palace to unlock its second slot. At which point you'd probably want to use the palace to declare VilB as capital, then knock it down and rebuild it at VilC.

This way, VilC has all three slots free.

You can do this several times - so build a palace to lv15 to use two slots. Knock down and do it again at another village. At the end though, you'd want the palace with your hammer so you can build three chiefs there.

Is knocking down the palace after unlocking its slots bad?
Well...not really. Having a residence or palace in a village doesn't really do much to protect it from being chiefed.

But if you are really worried I guess you can always rebuild a residence to lv1 after you knock down the palace. Or rebuild it to lv10... The first 10 levels of residence is very cheap. Last 10 levels is insanely expensive...

Organizing expansion slots is important
Well it's not difficult. At least if you understand it, it only takes a little fore planning. But it gives you two good things:
1. Three chiefs with your hammer. If you're roman and like big parties... 3 chiefs regularly does -80% or so of loyalty damage. Against a higher ranked player you often go above 90%.
2. Villages where you can build 2 chiefs. Obviously this is better than 2 chiefs in two villages... Easier to use and also means you only need to build the lv20 academy and lv20 residence once. Both of which are fairly expensive.

Slots that come with a chiefed village
VilA founds VilB
VilB founds VilC and VilD

Now say if I go and chief VilB off this player, in order to use any of the expansion slots at VilB. I will need to either destroy (0-pop) or chief VilC and VilD first.

In other words, often when you chief a village from another player, you will not be able to use that village to chief/settle further villages.

Another reason why it's a good idea to get your expansion slots organized in advance.