# Contract Bonus

Each ARC-Forge is assigned a random Contract Bonus type with equal probability when minted.

There are 4 types of Contract Bonus (CB), aligned to the 4 Upgrades with matching names:

* **Stability CB** - Increases the chance of building rare parts.
* **Tech CB** - Reduces the build time.
* **Enhance CB** - Increases part purity.
* **Precision CB** - Increases First Stage Success chance.

ARCs earn towards their **Contract Bonus** when they stay online and other ARCs go offline. The **Time Score (TS)** of an ARC is a measure of its relative online time, and determines an ARC's Contract Bonus.&#x20;

{% hint style="info" %}
**TS** depends on how long an ARC-Forge has been operational in idle or building state without going offline, compared to the activity of other players ARCs. TS has a base value of 5 and varies between 3 and 7.
{% endhint %}

Contract Bonus is only actived when TS > 5. This basically means that you need to be better than average to experience a performance boost from CB.&#x20;

You lose your accumulated CB immediately when you go offline, and it may take a while to regain it. However, other players are eventually incentivised to refurbish their ARCs to improve performance, which forces them to go offline.

A second huge benefit of keeping a high TS is an increased number of [consecutive builds in a multi-build.](https://alloy-space.gitbook.io/alloy-space/arc-forge-science/arcforge-functions#multi-build)\\
