If it's a tick, you're good to go - hit the button and they'll agree to be your Vassal. Next to the 'Demand Vassalization' button will either be a green tick or a red cross. Open up the 'Empires' tab, select the Empire you want to Vassalize, and click on the 'Communicate' button. To do this method, whoever you're trying to make your Vassal must be at peace. Once you've caused enough damage to this Empire, they will eventually contact you with details of surrender, in which case you can accept and they will become your Vassals. Drag the Vassalize option over from the available demands on the left to the selected demands on the right, and then hit Confirm. You can get more Warscore by raiding planets and destroying fleets belonging to this Empire. Here you can choose from a list of demands, each requiring a certain Warscore Cost to achieve. Select 'Declare War' on the right side of the menu, which will bring up the 'War Demands' screen. If I missed anything, make sure to call me out in the comments! Method 1: War There are a few ways of acquiring Vassals, which are listed below. Be wary of disloyal Vassals, as they may join an opposing Empire or attack you when on opportune moment arises (such as during catastrophic event or an invasion). Depending on your relationship with them, Vassals will either be loyal or disloyal to your Empire. Vassals also cannot colonize new worlds outside of their border range, and have no autonomy in relation to foreign policy or diplomatic relations. The subservient Vassals can be used to bolster your military ranks, as they will automatically join your wars - this applies regardless of whether you're attacking or defending, which can be very helpful when a larger Empire attempts to overwhelm you or you need few extra ships to take out an annoying fleet. Vassals are one of the types of Subject Empires that can serve you, and they're the Subjects that you can exert the most control over. What Are Vassals and What Are They Used For in Stellaris? Whether you want to conquer a species' homeworld and force them into servitude or liberate a species from the tyranny of another empire, there's a method for every play style when it comes to creating Vassals. While there are few different types of allies available in Stellaris, but this guide will focus on Vassals.

How to play stellaris species