We still want them to exist as a way to supplement one's army strength for ducats.

Province-level recruitment will probably have to go. Reducing click-fatigue while we're at it should be a priority.

The system should respect geopolitics: Mercs in India should be functionally different from Germanic ones.

Mercs must be finite to some degree. As an example, a prolonged 30 years war should drain Central Europe of available mercenaries, and said merc units should find themselves no longer able to reinforce.

Player involvement in the system must be greater than it is today

Late game multiplayer must be diversified from all out merc-on-merc warfare.

The system should be robust, feel alive, and enjoyable

Good day and welcome to this week's Dev Diary for EUIV. I'm sure it comes at an unforgivable late hour for many, but I have not long returned from a short trip to Lithuania. The country is a bit smaller than I remember, but Vilnius was a delightful place to spend the long weekend.I'm returning as forewarned by last week's Dev Diary to talk about ambitions for game mechanics in the upcoming European Expansion, slated for Q4 this year. As neondt has been discussing with maps and missions, I too will be sharing thoughts and ideas that we have regarding certain game mechanics. What is mentioned here are not changes that are currently in the game, nor are they promises of things to come, but more to share our thought process and ideas we have for the upcoming expansion and update.During the large end of year Dev Diary I mentioned various wishlist items that we would like to tackle in EUIV and on the list, right at the top, which with a degree of imagination is in bold, flashing colours and on fire, is that the current state of mercenaries in the game is long overdue for a shakeup. That's what we're here to talk about today.Firstly, why are we even talking about Mercenaries at all? Well Europa Universalis is a game about building Empires, and the business end of your stick are your armies. While regular armies are cost-effective for ducats, they can and likely will run dry of manpower in prolonged wars. Mercenaries exist for you to supplement your fighting force at an inflated ducat cost, allowing you to extend your own fighting capacity so long as your coffers can handle it. In the past, there was a limit to how many mercenaries were available to hire due to a 1% daily chance of mercs becoming available. This was removed in the interest of expunging the random element to available armies, and now your number of available mercs are tied to your forcelimit. Mechanically it's all very functional, but not without its issuesLook familiar? Once one's economy is in good shape, the go-to for a nation is to flesh out their army mercenary infantry and, should they feel decadent, mercenary artillery and keep that as a permanent solution for all aspects of warfare. They are the ultimate siege weapon due to reinforcing without need for manpower, so attrition is seldom a concern, while also being an entirely effective battle force as they take your nation's bonuses to battle, and any losses are very quickly recovered in exchange for money.Even in the event of your mercenary armies being wiped out, so long as you have the money, you are able to swiftly recruit as far as your force limit allows courtesy of their quick recruitment time, and within a few months, your armies march once more with renewed vigour and no impact on your manpower pool.Now to its credit, the way mercenaries work currently allows for a nation to always keep their momentum going. It can be no fun to simply sit on your thumb for manpower to recover for a war you want to fight if you find no other options available to you, and I'm sure most of us have found ourselves in a war which would have been all but lost if a few loans and an eager band of mercenaries had not been available to save the day.So what are our thoughts from here? Well, there is certainly no end to the balance tweaking that could be done here, as the variables involved are plenty and could be adjusted: rising cost of mercs, restricting their availability, perhaps reigning in how easily they adapt to all of your country's military traditions, fostered for centuries, within a few days. This could be done, and indeed it wasn't too long ago that we did increase mercenary costs across the board, but I believe the solution should be grander in ambition, to be fitting for the gravity of the Expansion we're planning for this year. @Groogy and I have hashed out thoughts on mercs with very much a "back to the drawing board" approach on the system. What has become more and more apparent is that the system as it exists is ripe for a full makeover.The European Expansion and its update will, in all likelihood, feature a completely different mercenary mechanic from what we know today. We have established several key aspects of how we want to handle mercenaries:In addition to this, we want to make the fundamental changes to the merc system part of the update. All players who get the planned Q4 update should enjoy a new merc system to explore.The Dev Diary may end up raising more questions than it answers regarding mercs, but this is not the last we'll be talking on the matter. This and various other DDs to follow are to shed light on our internal thoughts regarding development, rather than showing off what we have added to the game. I'm sure you're growing tired of hearing it by now, but we continue to iron out tech-debt issues (which really deserve a dev diary of their own) and gearing ourselves up for developing this large European Expansion.What are your thoughts on the existing mercenary system and what would you like to see in a new update? Let us know in this thread, and we'll be back next week to talk more on our plans for the upcoming Q4 Expansion and Update