Enclosure (Annexation) Guide for OpenFront.io
Main Takeaway: Enclosure—also known as annexation—allows you to capture entire territories by fully surrounding them, bypassing protracted battles. Mastering enclosure accelerates expansion, conserves troops, and can swing the tide in your favor early and mid-game.
1. What Is Enclosure?
Enclosure occurs when you completely encircle an adjacent territory (bot or player) so that it has no open border connections. Once surrounded, the territory is instantly annexed—all its land transfers to you without further combat.
2. Why Use Enclosure?
- Troop Efficiency: Annexation uses only the initial attacking stacks, with no additional losses afterward.
- Speed: Instant capture skips multi‐round exchanges.
- Map Control: Rapidly grows your land and resource generation.
- Psychological Impact: Surprising an opponent with enclosure can force them into defensive play.
3. How to Execute Enclosure
3.1. Preparation
- Build Population:
– Raise your population to ≈ 40 – 50% of cap to maximize growth rate (peak at ~41%). - Scout Terrain:
– Press Spacebar to reveal terrain and neighboring territories; identify narrow fronts or chokepoints.
3.2. Choosing the Target
– Bots First: Ideal initial targets due to predictable, static borders.
– Real Players: Wait until they’re engaged elsewhere or have stretched borders.
3.3. Calculating Attack Size
– Optimal Percentage: 40 – 50% of your troops balances speed and losses; higher percentages move faster and suffer fewer casualties.
– Attack Ratio Adjustment:
- In the attack panel, adjust your troops-to-worker ratio to maximize movement speed without crippling your economy.
3.4. Executing the Enclosure
- Multi-Front Push: Simultaneously attack from all bordering sides of the target territory.
- Timing: Coordinate so all attacks land within the same tick, closing gaps instantly.
- Split Attacks: If terrain forces asymmetrical fronts, use smaller attacks on narrow sides to seal off escape routes.
4. Advanced Enclosure Tactics
| Tactic | Description |
|---|---|
| Choke-Point Enclosure | Use rivers, mountains, or coasts to reduce the number of fronts you must attack, sealing the territory more efficiently. |
| Feint and Seal | Send a small force as a feint on one side, drawing defenders, then launch your main enclosure force on the opposite front. |
| Ally Buffer | Form temporary alliances to occupy adjacent territories, preventing opponents from reinforcing the target you intend to enclose. |
| Follow-Up Infrastructure Push | After enclosure, immediately plant cities on newly acquired borders to raise your population cap and prepare for the next push. |
5. Defending Against Enclosure
- Maintain Open Exits: Always leave at least one border connection to a friendly or neutral territory.
- Defense Posts & SAMs:
- Defense Posts quintuple the cost of conquest around them—use them to protect chokepoints.
- SAM Launchers cannot prevent annexations but deter aerial bombardments during multi-front attacks.
- Alliances & Betrayals: Do not accept alliance requests from neighbors you suspect aim to enclose you—they gain a +50% casualty penalty on betrayal, leaving you vulnerable if you refuse.
6. Common Pitfalls
- Oversized Attacks: Deploying > 60% of your troops slows movement drastically; use moderate percentages.
- Poor Timing: Staggered attack arrivals leave gaps for defenders to reinforce or counterattack.
- Ignoring Economy: Draining troops for enclosure can cripple gold income if your worker ratio falls too low.
Citations
“Openfront.io Beginner’s Guide: Mechanics, Tips, & Tricks,” YouTube, Jun. 30, 2025.
“The ULTIMATE OpenFront.io Tutorial and Strategy Guide!,” YouTube, Apr. 29, 2025.
“How to Play Openfront.io For Beginners (Tutorial),” YouTube, Jun. 05, 2025.