OpenFront Naval Strategy Guide
The sea decides matches quietly: it carries your trade, hides your invasion, and bypasses the mountain border you spent the whole game defending.
Quick answer: build warships to protect trade and to punish unprotected coasts. A sea invasion commits troops ÷ 5 — the same share as a ground attack — so an amphibious push is worth it exactly when your opponent's army is inland.
The naval toolkit
| Asset | Cost / stat (live build) | Role |
|---|---|---|
| Port | min(1,000,000, 125,000 × 2ⁿ), 5 s build | Prerequisite for naval play; also your trade hub |
| Warship | min(1,000,000, 250,000 × (n+1)) | Patrols water, sinks trade ships, supports landings |
| Warship shell | 250 damage, 2 s flight time | Short range but decisive against ships and coastal structures |
| Transport / invasion | troops ÷ 5 per order | Lands troops across water to open a second front |
When naval play is worth it
- Your trade runs through contested water — a single hostile warship can erase your income; escorts are cheaper than rebuilding ports.
- Your opponent's coast is undefended — the cheapest tiles in a mature match are often behind a beach nobody garrisoned.
- You are boxed in on land — water is the only remaining direction to expand or raid.
- You share a sea with an ally — a joint landing on a third player's coast is the classic naval play.
How to invade by sea
- Clear the water first — warships beat transports; landing into a contested sea usually means losing the army.
- Pick a coast behind their army — the point of a landing is that the defender is somewhere else.
- Bring enough for a beachhead — a landing that cannot hold the first tiles is a donation; reinforce immediately if it works.
- Take something worth having — a port, a chokepoint or an undefended economic core, not an empty peninsula.
- Expect the counter-landing — the player you invaded will look for your coast next; keep some army home.
Coastal defence checklist
- One defence post behind each beach you actually care about — terrain does not help you at the waterline.
- Warships on station in the water next to your ports, not parked in a corner.
- Knowledge: track which neighbours own ports, because ports are how they reach you.
- Redundancy: two ports on separate routes survive losing one.
FAQ
Common questions about this topic.
How much does a warship cost?
min(1,000,000, 250,000 × (n+1)), where n is the number of warships you already own — 250,000 for the first, rising to a one-million cap.
How do I invade another player across water?
Build ports, clear the water with warships, then order a landing; a boat attack commits troops ÷ 5, the same share as a ground attack.
Why are my trade ships being sunk?
Almost always a hostile warship on your route. Escort the route or move it; escorting is usually cheaper than rebuilding ports.
Is naval play necessary on land maps?
No. If the map has no useful water, ports and warships are wasted gold — put it into cities and factories instead.