Frequently, especially for early wars with so many nations, like the majority. You dont have professionalism anyway at that point and mercs have a high chance of having a siege pip general, which also greatly helps in early war sieges. You are missing out if you dont use them.

Originally posted by Narrowmind:

They have their uses. The free company is always in service for many players early in the game. They also can come with quality generals that may be out of reach for a player depending on available tradition. Lastly, they also come with their own manpower pool, so if numbers are an issue, they make a fair suppliment.

Nice summary, Narrowmind. I hire the Free Company as literally every nation. It's actually cheaper than normal troops at the start of the game (how much so depends on your development) and of course it gives a supplemental manpower pool. The available generals may or may not be useful, depending on how my rolls for generals are going. But the extra manpower pool mercenaries provide can be crucial early on. Manpower is a limiting factor for most nations during the game's first century. It's easy to burn through it much faster than you earn it until you blob out and also construct useful buildings.

So to the OP, yes, I use mercenaries in every single campaign of EU4.

There's some niche cases with specific countries where their national ideas support mercenary use, in which if you play that country (or you retain those national ideas after changing into another country), take Mercenary Ideas, and pick government reforms that boost mercenaries, you can theoretically make mercenaries pretty good... but it's sort of one of those things where you either lean hard into it for the sake of leaning hard into it, or, you use them sparingly (as the others said - early game they're good relief for your country's manpower and weak generals; later game the main use is if you're in a war and your enemy has Hannibal'ed halfway around the continent to sneak armies in your undefended flank and you won't be able to get your main forces back quickly enough, so you could opt to take the professionalism hit by spawning a mercenary company to fend the enemy off).

Venice mercenaries right now are stronger than regular troops and they have near infinite manpower so you can just assault every fort.

Originally posted by McLongboy:

Even if youre playing as a small rich nation you are better off using normal troops. Less expensive, doesnt decrease professionalism.

What you're describing is accurate to mercenaries in the mid to late game. However, as above, in the early game mercenaries are extremely useful. They allow you to punch well above your own weight and expand much more aggressively in first few decades, whereas you might find yourself completely blocked off from further expansion if you limited yourself only to manpower troops.

As an addition, as long as your nation's total development is below 150, you have access to a special version of the Free Company that has a whopping -70% cost modifier, making them straight-up cheaper than manpower troops in exchange for some minor and largely irrelevant penalties to reinforcement and morale recovery speed. As with mercenaries in general, this development limitation means you won't be able to make use of them for a very long time (you could just never disband them, but the small stack will become increasingly irrelevant the more you grow), but they are a valuable asset for your first few wars.

Originally posted by McLongboy:

If mercenaries didnt add to the force limit cap then there would be a pretty good niche for them

That would just be ridiculously strong. Depending upon the size of the nation and how far into the game you are, that would be basically equivalent to giving everyone in the game an extra 20k to 500k extra Force Limit.

In addition to the above, they can be useful later in the game due to how quickly they arrive somewhere. Moving a corps of troops halfway around the world in response to a random event revolt or the like can be slower AND more costly in terms of resources (manpower and ducat reinforcement costs) than just plopping down a stack of mercs, not to mention being more hassle.

I always use mercenaries for my colonies and trade companies. Historically accurate, but more important why waste your manpower fighting colonial wars. If late game you can't afford mercenaries, you are playing EU IV wrong.

Mid game they allow you to take forts quickly. You create a breach and then assault. Their manpower is "free", it is a good tool to keep your manpower before the garrison become available and manpower a secondary parameter as you recover it faster than you use it.

In many cases manpower losses would be a concern so I throw some mercs into the more dangerous areas - if they get killed or take horrendous losses who cares? Especially useful when trying to bait the AI into attacking you where you would get terrain bonuses but the bait will take a lot of damage...

Nah man. If you play an aggressive early game you pretty much HAVE to rely on mercenaries, since your manpower cant keep up.

Originally posted by Marquoz:

So to the OP, yes, I use mercenaries in every single campaign of EU4.

I personally dont always, but not using them slows the game down a lot.

I usually start of with mercenaries, and when i grow to 50-100k total manpower i transition to a pure standing army to increase my professionalism.

It isnt the most efficient thing, but i prefer it this way. Midgame mercenary companies tend to bloat to 40-60 units per stack whilst the average supply is around 30. Them taking attrition barely matters of course due to their insane manpower pool (around 150k for a 60 stack) but i just dont like the idea of units taking permanent attrition.

Mercs are ultimate win condition in any game. Win as OPM Vs Otomen? Just hire mercs. Florry doing it every stream without allies and loans on VH.
I did it few times playing obsurce OPMs on VH too, with loans tho. sadge.

But for regular EU4 enjoyer, y always hire free company at the start, plus any company with amazing general if you can aford it

Originally posted by bydlaq:

Mercs are ultimate win condition in any game. Win as OPM Vs Otomen? Just hire mercs. Florry doing it every stream without allies and loans on VH.
I did it few times playing obsurce OPMs on VH too, with loans tho. sadge.

But for regular EU4 enjoyer, y always hire free company at the start, plus any company with amazing general if you can aford it

Dont tell me Florry is using mercs as OPM without loans. Florry is a skilled player, but he is no magician or cheater. In fact, many of his early game strats even go so far to border bankruptcy. But thats where his skill shines, he can do all that and come out winning and stabilized. He is still in the same position as you and me at the start though, we pushed the same buttons and have the same amount of money. If i go in debt for mercs, he will too. Especially early on where Burgher loans are basically a staple to get as everyone.

Loan juggling is an art form for Florryworry, so much so that the popular strategy of taking new, bigger loans in order to pay off your many older, smaller loans is often referred to as "Florrynomics".

I can think of one further reason for using Mercs - Colonial expansion/wars

Lets say you have a Province In Africa you captured/seized Colony and you only have one in that area - you are not going to click 30 times to make a stack in that area!

I had a scenario recently where I was at war with a rival and wanted their Colonial provinces - I did not want to transport troops 1/3 way round the world and risk attrition and possible loss of some transport ships to roving enemy Navies and I needed my war navy back home to suppress their fleet

I also realised l that I had several enemy small stacks moving in Africa (looked back at the region after some fighting in Europe) and if I did nothing a small national army would be potentially destroyed (it was 40KPlus vs 30K of mine) - so I hired Mercs which took me 9 days and completely turned the situation around and routed them

TLDR:

National Armies are better BUT you can't be everywhere and sometimes its not practical for your army to be somewhere - and it was needed somewhere else.