> For the complete documentation index, see [llms.txt](https://pioneers.gitbook.io/pioneers-whitepaper/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://pioneers.gitbook.io/pioneers-whitepaper/game-mechanics/trails.md).

# Trails

We can imagine trails arranged in a tree-like structure. The wagons will start on the trails at the lowest level. As the game progresses, they will merge into fewer and fewer trails until they merge into a single final one.

<img src="/files/7ZxPM3NvYE0HBSHzERo5" alt="An example scheme depicting trails." class="gitbook-drawing">

When an NFT is minted, the owner must specify the starting trail for their brand-new wagon from the bottom eight (8-15).

## Game phases

The entire game progression is divided into *phases*:

1. *Initial;*
2. *Minting;*
3. *Journey1* (trails 8 to 15)*;*
4. *Journey2 (*&#x74;rails 4 to 7)*;*
5. *Journey3* (trails 2 and 3)*;*
6. *Journey4* (trail 1)*;*
7. *Destination* (one wagon remaining)*;*

At this time, it is natural to wonder, what is the event that will trigger the transition to the next journey phase? Simple, when the first quarter of wagons is destroyed. Generally, each quarter of destroyed wagons will trigger the transition to the next level.

For example, let's say a total of 400 wagons were initially minted and the game starts (*Journey1* phase). Once the number of wagons drops to 300 (100 wagons destroyed) the smart contract will generate inconvenience sets for the next trails (i.e. trails 4 to 7), entering the *Journey2* phase. Intuitively, all wagons traveling on the trails below will move to the trail directly above (eg. wagons traveling on trails 8 and 9 will be moved to trail 4).

{% hint style="info" %}
Unlike the victim letter and the suffered inconveniences that use the *blockhash randomness*, inconvenience sets for new trails are generated randomly through [Chainlink VRF](https://chain.link/vrf).
{% endhint %}

## Inconvenience sets

Each level of the tree differs in the type of inconveniences that can be generated:

* Trails from the bottom level (i.e. trails 8 to 15) have 3 types of inconveniences each.
* Trails from the penultimate level (i.e. trails 4 to 7) have 6 types of inconveniences each.
* Trails from the second level (i.e. trails 2 and 3) have 9 types of inconveniences each.
* The top-level trail has 12 types of inconveniences.

## Switching trails

By paying a small fixed fee, you can move your wagons between trails. This choice is well-motivated if another trail is more suitable (in terms of inconveniences) than the one on which your wagon is currently traveling. Obviously, the fee goes into the prize pool.&#x20;

$$
Price = MoveBaseCost \* JourneyPhase
$$

For instance, if the current phase is *Journey3,* the price will be:

$$
Price = BaseCost \* 3
$$