New to EU5? This guide is part of the EU5 New Player’s Path. If you are just starting, follow the Path in order instead of jumping between systems.

Patch 1.4 note: Update 1.4 “Río Salado” launches October 28, 2026 and changes cavalry strength, mercenary costs, and siege rules. The core levy and professional system below stays the same. Jump to what changes in 1.4 for the details.

Building and managing an army in EU5 is different from EU4 in one crucial way: EU5 uses a dual army system with levies and professional troops. Understanding the difference between these two forces is the most important thing a beginner needs to know about EU5 combat. Here’s how it works. And if you would rather experiment than read, the interactive EU5 Army Battle Lab lets you build a force against an AI opponent and see exactly how it performs.

Source: Paradox Interactive, official EU5 Steam screenshot

The Two Armies: Levies and Professionals

Levies are the citizen militias that rally to your banner when you go to war. They’re the bulk of your early army, and they have distinct characteristics:

• They’re temporary. Levies are summoned when war breaks out and disband when it ends.
• They’re plentiful but weak. You can raise large numbers of them, but they’re poorly trained and equipped compared to professionals.
• They spawn from your provinces. Your levy pool comes from your population, so a larger population means more levies.
• They’re cheap. Levies cost little to maintain during war, which makes them attractive for early-game economies.

Source: Paradox Interactive, official EU5 Steam screenshot

Professional troops are your standing army. Trained, equipped, and always ready:

• They’re permanent. Professionals stay in your army during peace and war alike.
• They’re expensive. Professionals cost significantly more to maintain than levies, both in gold and in upkeep.
• They’re reliable. Professionals fight far better than levies, with higher discipline and morale.
• They’re limited by your economy. You can only maintain a certain number of professionals based on your budget and military infrastructure.

Why This Matters

Source: Paradox Interactive, official EU5 Steam screenshot

The levy/professional split changes how you think about war in EU5:

Early game. You’ll rely mostly on levies, with a small core of professionals. Your army is large but fragile. You can win wars, but you need to win them quickly before your levies’ morale collapses or they take unsustainable casualties.

Mid game. As your economy grows, you transition toward a professional core. Your armies get smaller but stronger. You can fight longer wars because your professionals don’t disband.

Late game. A fully professional army is the goal. It’s expensive to maintain, but it’s the most reliable fighting force in the game.

Building Your Army

With the two-army system in mind, here’s what a balanced military looks like:

Early game:

• A small professional core (a few thousand men)
• Large levy armies raised for specific wars
• Accept that your levies are expendable. They’re there to win the war, not to survive

Mid game:

• A growing professional army as your backbone
• Levies used as auxiliary forces or for defensive wars
• Invest in military buildings that improve both your levy pool and your professional capacity

Late game:

• A fully professional army as your main force
• Levies kept as a reserve for emergencies
• Professional armies are expensive, but they win wars

Managing Your Military

Source: Paradox Interactive, official EU5 Steam screenshot

1. Don’t waste your professionals. Professional troops are expensive to replace. Use them for decisive battles, not for garrison duty or siege support.

2. Levies are expendable, use them that way. Levies are there to absorb casualties and win wars. Don’t be precious with them.

3. Watch your economy. A professional army can bankrupt you if you build it too fast. Grow your professional core as your economy allows.

4. Use terrain and tactics. Defending in mountains or across rivers gives you a massive bonus. Let the enemy attack you in bad terrain, regardless of which army type you’re using.

Common Beginner Mistakes

• Treating levies like professionals. Levies are not your real army. They’re a force multiplier. Don’t expect them to fight like trained soldiers.
• Building too many professionals too early. A professional army is expensive. Build it as your economy grows, not before.
• Ignoring your levy pool. Even in the late game, levies are useful as reserves. Don’t let your levy pool sit unused.
• Forgetting maintenance. At peace, lower your maintenance costs. Raise it to full before going to war.

What Changes in 1.4

Patch 1.4 does not replace the levy and professional system, so everything above still applies. It does change the numbers around it. These are the military changes confirmed in the official developer diaries and beta, and the figures below are the ones previewed so far, so treat exact values as subject to change until you check the final patch notes.

Cavalry gets weaker. Cavalry combat power drops from 4 to 3.25. The flanking bonus is cut from +110% for light cavalry and +100% for heavy cavalry down to +60% for both. In practice, an army that leaned on cavalry flanks in 1.3 will need more infantry and artillery to hold the same line.

Mercenaries cost more. Hiring costs roughly twice as much upfront, monthly upkeep is about 35% higher, and mercenaries eat about 50% more food in the field than regulars. Hiring on rival-owned soil adds a default 25% hostile territory surcharge. For a beginner, this makes mercenaries a short-war emergency tool, not a replacement for a professional core.

A new Mercenary Market law arrives in the Age of Renaissance. It has four options: Condottieri Business, Open Markets, Restricted Markets, and Unrestricted Market. Unrestricted Market is the 1.3 default.

Napoleonic Warfare is reworked. The advance now grants +5% discipline instead of ignoring zones of control.

Sieges get a small first step. Artillery now needs 2 regiments per bonus point against forts instead of 3, and forts auto-surrender below 5% garrison strength instead of below 10 defenders. The developers say a larger siege rework is planned for 1.5. Our 1.4 combat and siege guide covers both in depth.

Estates can field private armies. The Nobles and Cossacks get their own regiments in 1.4. See the estate private armies guide.

What this means for a new player: build your first army around infantry and artillery, treat cavalry as support rather than the main force, and keep mercenaries for emergencies. Test your own mix in the EU5 Army Battle Lab, and follow every confirmed change on the 1.4 “Río Salado” hub.

The levy/professional system is the defining feature of EU5’s military. Learn to use both forces effectively. Use levies for scale and expendability, professionals for quality and reliability. As your economy grows, transition toward a professional core while keeping your levies as a reserve.

The key insight: EU5’s military is about resource management, not just army composition. You’re managing two different forces with different costs, different strengths, and different roles. Master both, and you’ll have a military that can handle anything.

Try It Yourself

Want to see how composition decisions play out? Our EU5 Army Battle Lab gives you and an AI opponent the same 100-point budget to build armies, then fights the battle and explains what happened. It is a great way to feel why Regulars beat Levies and why Artillery changes the opening.

Next in the Path: Societal values (Stage 4).