Nova Roma Invasion Defense Guide: Militia, Towers & Walls

Invasions in Nova Roma arrive without much warning, and if your city has no defenses ready, you will watch buildings take damage while your population scrambles. The good news is that the defense system here is straightforward once you know what to build and in what order. Two core tools stop invaders cold: militia and guard towers. Get both running early and you will rarely lose a building to raiders again.

What are invasions in Nova Roma?

A few in-game years after your settlement takes shape, one of the Roman gods sends a warning that raiders are heading your way. Shortly after, an enemy ship appears off the coast. The invaders land, move toward your buildings, deal damage to a few structures, then retreat.

In the early game, these raids are light. The attackers may even leave on their own after causing minimal damage, especially if your city is still small. That changes fast. On higher difficulty settings, invasions come more frequently and hit harder, forcing you to split resources between citizen welfare and active defense. Ignoring the threat on harder modes is not a viable strategy.

You can check out the game's community discussions and updates on the Nova Roma Steam Community page to see how other players are handling defense strategies.

How do you recruit militia in Nova Roma?

Militia is your fastest and cheapest first line of defense. To recruit them, click on your outpost and press the Recruit button. A group of militiamen forms up shortly after, ready to engage any raiders who enter the settlement.

The catch is that militia are pulled directly from your civilian population. Every fighter you recruit is one fewer worker contributing to food, construction, or resource gathering. The civilian count recovers naturally as immigrant ships arrive at your docks over time, so this is not a permanent loss, just a temporary trade-off.

Outpost recruit button location

The practical approach is to keep militia active at all times unless your city faces a serious labor shortage. If you desperately need workers for a construction push, you can disband the militia through the same outpost menu. The former fighters return to civilian roles immediately. Rebuild them once the construction sprint is done.

How do you build guard towers in Nova Roma?

Guard towers are unlocked through the Favor Menu inside your temples. As your city grows and you make offerings to the gods, new structures become available, including progressively stronger towers and wall segments.

Placing a tower opens a highlighted radius showing the area it covers. Position towers to overlap coverage zones where possible, particularly near the coastline or any likely approach routes. Archers stationed in the towers will automatically engage any invaders who enter range, dealing continuous damage without you needing to micromanage the fight.

Building towers costs gold, which you generate by constructing a tax office. The tax office collects gold from residential buildings within its service area, so expanding your housing district also expands your gold income. Prioritize the tax office early to keep your defensive construction funded.

Tower coverage zone placement

Walls: the force multiplier your towers need

Towers alone work, but walls make them dramatically more effective. Building a wall around key areas of your city forces invaders to attack the wall itself rather than your production buildings. While raiders are occupied battering the wall, your tower archers have extended time to whittle them down.

Walls are also unlocked through the Favor Menu as your temple offerings increase. The combination of walls funneling attackers and towers covering the approach is the most reliable defense setup in Nova Roma. Prioritize closing off the most exposed side of your settlement first, typically the coast-facing edge where the enemy ship lands.

Comparing your defense options

Building a layered defense: the right order

The most effective approach is to layer all three systems rather than relying on any single one. Here is the recommended build order based on what the game makes available at each stage:

• Recruit militia first. It costs nothing but population and is available from day one. Always have fighters ready before the first invasion warning arrives.
• Build a tax office early. Gold is the bottleneck for towers and walls. Getting gold income running in the first few years prevents a defensive funding crisis later.
• Unlock and place guard towers as soon as they appear in the Favor Menu. Position them to cover the most exposed approach routes.
• Add walls once your gold reserves can support it. Focus on enclosing the areas your towers already cover to create overlapping kill zones.

For a deeper look at the invasion system and additional tips from the community, the Into Indie Games walkthrough on Nova Roma invasions breaks down the mechanics in detail.

For more city-builder guides and strategy breakdowns across a wide range of games, browse the latest guides on GAMES.GG to keep your strategy sharp.