A very general "everything welcome" brinstorming about what an emperor of some sort of a space empire can/should do? What are his daily routines what is his job?

Alternatively, you can note what he is not supposed to do.

It's for a strategy game that simulates a space emperor (rather then the space empire), so a game more from the point of view of the person, the emperor.

He sits around, eats snacks and lets his governors do the work I would say, but that wouldn't make a very interesting game...

:) Not if everyone wants to assinate him and he needs to check if these snacks are not poisonous (or to be precise determine which ones are the poisonous ones and whom he should behead for this) :D

Audience - he sits on the throne and people and coming in and he needs to sort out various issues (while not having the time to deal with them all)

Assigns ministerial positions/officials of all sorts

Gives out medals and promotions to officers

Fights his brother who want to usurp the throne

I see the Emperor as an analogy of corporate business high-level management (often called "Strategic Management").

My personal experience is that of video game development, and I've noted this:

- Provides budget, allocates resources and defines an objective.

- Receives key indicators/metrics of smaller-scale (projects/orders) developments and how close they are to achieving the intended result.

In other words, as an Emperor (or anyone from high management) you should:

In the context of a mission:

- Allocate budget and people, and demand an objective (Attack Tau Ceti for conquest, you can use everyone you need from Squadron Corps 22T (approx 1000 soldiers) and up to 130K$. I want this done as of date X.

Then, your underlings will assemble a fleet that they believe fits the budget, and can get the job done before the end-date. They will launch the operation and report on their progress. It is quite possible that they will inform you of their inability to provide the necessary result given the circumpstances which you have set, and you will hav an opportunity to act if necessary to either perform damage control (aborting the project perhaps) or see it through by adding additionnal resources ($, people, or time). You might also revise the scope of your operation, for example, limit the conquest to planet X-22 of the Tau Ceti system.

Random mechanics:

The emperor is sitting on a throne and there is an audience. You have a pool of "money" and "people". Various officials come to you and ask for resources, you decide (one by one) if to grant it or not. The trick is you don't know who will come next and how important the next request might be, so you can't determine perfectly how much mony you can still spend safely (maybe the last one will come with an info about an invasion?)

Military (fleet and land imperial infantry regiments) could be as "tokens". You don't move them on any map but "assign/borrow" to certain task (upon request). For example an official come in and says they might have detected aliens near planet X and request scout ships squadron. You would have 3 options regarding how many ships to send (if any), and then all the assigned ships will be locked (unavailable) for X days.

Something like this:

Random mechanics:

The emperor is sitting on a throne and there is an audience. You have a pool of "money" and "people". Various officials come to you and ask for resources, you decide (one by one) if to grant it or not. The trick is you don't know who will come next and how important the next request might be, so you can't determine perfectly how much mony you can still spend safely (maybe the last one will come with an info about an invasion?)

Military (fleet and land imperial infantry regiments) could be as "tokens". You don't move them on any map but "assign/borrow" to certain task (upon request). For example an official come in and says they might have detected aliens near planet X and request scout ships squadron. You would have 3 options regarding how many ships to send (if any), and then all the assigned ships will be locked (unavailable) for X days.

That really doesn't make much sense. The last person in line brining news of an invasion would likely have badgered someone with the important news, and a group of high level officials would have pushed their way to the front of the line. If they were late and came at the end anyway, then the emperor would simply whistle get everyone's attention again and say "Well, sorry chaps, all your stuff is canceled, found something more important."

May I suggest reading Dune: House Atreides (1999), Dune: House Harkonnen (2000), and Dune: House Corrino (2001)? They deal with high politics in a space empire, and may give some ideas of what can actually be done.

Issuing proclamations and such

That really doesn't make much sense. The last person in line brining news of an invasion would likely have badgered someone with the important news, and a group of high level officials would have pushed their way to the front of the line. If they were late and came at the end anyway, then the emperor would simply whistle get everyone's attention again and say "Well, sorry chaps, all your stuff is canceled, found something more important."

Well, having a reference of Risk assessment could help.

Project Management is a lot like managing this kind of chaos, and, for a job, its actually fun. I'm just not sure you can easily gamify this.

Mostly, an emperor would be dealing with attempts to dethrone him.