Isleborn Kingdoms: How to Play and Win This Free Strategy Game

By HSP · Published October 12, 2026 · 9 min read · Games

We wanted a strategy game you could open on a phone during a bus ride and still be thinking about that evening. That meant a real map, choices that matter several turns later, and no timer pushing you. Isleborn Kingdoms is turn-based, plays against computer clans and saves on your device, so you can stop halfway through a realm and pick it up the next day.

Below is how each part works and what we learned from playing it a lot while building it.

The map: a new island every realm

Each realm is generated from its number, so realm 12 is the same island for everyone, but no two realms look alike. You get meadows, pine forests, hills, grey mountains with snow on the peaks, beaches, inland lakes and rivers, and old dirt roads joining the castles. Islands start at 14 by 10 lands and grow to 36 by 24 in the late game, with up to four rival clans.

The terrain changes the fights. Forests, hills and mountains are harder to take. A river adds 15% defence unless a road bridges it. Any land with only one or two land neighbours is a choke point and defends 20% better. One well-guarded choke point can hold a whole flank while you push somewhere else. The terrain also pays: hills and mountains give gold and stone, meadows give food, forests give wood and roads add trade.

You see only three steps past your borders. Beyond that the island sits under drifting cloud. Scouted land stays lightly shaded and any enemy castle you have spotted stays on the map. Pushing a thin line deep into fog is tempting, but widening your border first shows you what you are about to fight.

The island is drawn in isometric 2.5D. Hills and mountains rise above the meadows, castles cast shadows and rivers run down into the sea. Drag to pan and pinch or scroll to zoom. On a slow phone, zooming out drops the small details so it stays smooth.

Six worlds, six twists

Every ten realms you sail to a new world. Each has its own colours, its own music and its own rival clans, plus one rule that changes how you play:

• Verdant Isles (realms 1 to 10): gentle green islands where you learn the ropes.
• Sunscorch Desert: sandstorms roll in and hide everything past your border for a turn. Kesh the Dune Rider joins you here.
• Frostpeak Reaches: deep snow slows your march, so attacking snow or mountains uses two attacks. Clearing the desert unlocks the Desert Bazaar.
• Emberforge Volcano: eruptions turn lands into new mountains and scatter their guards. The Ember Forge unlocks here.
• Skyreach Isles: floating islands. Spend wood to build bridges across the sky, and watch for clans building their own. The Sky Dock unlocks here.
• Shadowfen Realm: thick shadow cuts your vision, and Nyx the Night Owl can light up the whole island for a turn.

Four troop types and the counter triangle

• Spearmen are cheap and beat Riders.
• Archers cost some wood and beat Spearmen.
• Riders are the strongest and dearest, and they beat Archers.
• Catapults cost stone and do not fight on their own. Each one you bring strips away part of the defender's bonus from walls, terrain, rivers and choke points. If Riders make up a big share of the garrison, catapults only do half as much. Win and they come home; lose and they are gone.

A troop deals 50% more against the type it beats and 30% less against the one that beats it. Tap any land and the panel shows its exact garrison and your win chance, and the chance updates as you add or remove troops and catapults. Best mix drops troop types that would only be wasted.

Four resources and your home base

You collect gold, food, wood and stone every turn. Seven buildings carry over from realm to realm: Farm, Coin Mint, Lumber Mill, Stone Quarry, Barracks (more troops per turn), Watchtower (defence) and Great Hall (extra attacks). Higher levels start costing stone, so a Quarry that lags behind will hold everything else back by realm 15 or so.

The research tree

Research is the long game. There are nine techs in three branches, and each branch unlocks in order:

• Military: Tempered Steel (+10% attack), Shield Wall (+15% defence everywhere), Siege Craft (catapults work 50% better).
• Economy: Crop Rotation (+25% food), Masonry (+50% stone, cheaper buildings), Trade Roads (owned roads pay three times as much).
• Statecraft: Cartography (see further through fog), Envoys (cheaper diplomacy), Legends (your hero's skill twice per realm).

Our usual order is Crop Rotation, then Tempered Steel, then Masonry. Food funds the army, steel makes every attack cheaper, and Masonry pays for itself within a few realms.

Heroes

One hero leads your army at a time, and you can switch between realms. Heroes gain a level every five victories, which strengthens their passive.

• Captain Rowan makes Spearmen fight harder. His skill, Rally, makes your next attack 50% stronger, which is exactly what you want against a castle.
• Ranger Lyra (unlocks at realm 5) gives an extra attack every turn. Volley scares off 35% of the guards on an enemy land next to you before you go in.
• Warden Bram (unlocks at realm 10) hardens your castle. Fortify makes all your lands defend 50% better for two turns, which saves you when two clans hit you at once.

Diplomacy

From turn three the clans start attacking, and they go for whichever of your lands looks weakest. Diplomacy lets you pick your fights. A truce stops a clan attacking you for five turns. An alliance lasts ten turns and the ally sends you two Spearmen and an Archer every turn. In return you cannot attack them. You can break a pact, but that clan comes back angrier and with more troops.

Two limits keep it fair: you can never make peace with the last clan standing, and boss stronghold lords never negotiate.

Boss strongholds and the ending

Every tenth realm holds a stronghold, marked with a crown on the realm map. Its lord, from the Iron Warlord in realm 10 to the Obsidian King in realm 60, sits behind thicker walls with a much bigger garrison and a ring of fortified lands, and that clan grows faster than the others. Taking a stronghold pays three times the usual reward.

Beating the Obsidian King in realm 60 unites Isleborn and ends the campaign. Your heroes, buildings and research then carry on into endless realms that keep growing.

Reasons to come back tomorrow

The campaign has an ending, but most of our own play time now goes into the other modes.

• Weekly event. Each week a named boss arrives, such as the Frost Wyrm or the Storm Kraken, and a banner on the main screen shows when the event ends. The goal is simple: keep your castle standing until day 7 while the boss throws more and more at you. Survive it once and you earn the Survivor banner.
• Daily challenge. Everyone gets the same island each day. Win in as few turns as you can, then share a one-line result with friends and compare.
• Conquest. An endless chain of islands that get bigger and meaner. One fallen castle ends the run, and your ten best runs sit on a personal leaderboard.
• Random events. Some turns bring a travelling merchant with a deal, a storm that scatters a garrison, a rebel uprising that takes a land back, a gold strike or volunteers.
• Idle income. Your kingdom keeps earning while you are away, up to four hours' worth, waiting for you on your return.
• Reward track. A bar under the resources counts your wins, and every eighth win opens a chest with gold, stone and a free catapult. It is usually only a win or two away, which is how "one more turn" turns into twenty.
• Banners and castle skins. Thirteen cosmetics, all earned by play and none for sale: win 25 battles for Emerald, beat a stronghold for Royal, or unite Isleborn for the Golden Palace.

Tactics for the harder realms

1. Bring catapults to castles, not to meadows. On open ground there is barely any bonus to strip, so they are wasted.
2. Check the Riders first. If a castle is guarded mostly by Riders, send Spearmen to deal with them, and expect less from your catapults.
3. Truce with the neighbour, kill the far clan. Buy five quiet turns on one border and spend every attack on the other.
4. Hold choke points with small guards. The 20% bonus stacks with terrain, so a guarded pass on a hill is very hard to crack.
5. Save the hero skill for the castle. Rally or Volley on the final assault is worth more than on any wild land.
6. Go for the castle when it is exposed. Capturing it wipes out the clan and frees all its lands at once.

The first two minutes

New players get a short tutorial in a yellow bar above the map. It walks you through six steps: pick a land, attack, train, end the turn, upgrade the Mint and open Research. The button you need glows, every tap clicks, and finishing the tutorial gives you a starter bonus. The first three realms are softer, and clans hold off for a few extra turns, so nobody loses their castle before they know what Fortify does. The current goal is always shown under the reward bar.

On a phone

Every panel slides up over the map, so you never lose your place. On a computer you can also zoom with the mouse wheel and pan with the arrow keys.

Is it safe for kids?

Yes. There is no chat, no online play, no account and nothing to buy. Battles are flags and marching icons, not gore. Progress lives in your browser's local storage, so clearing site data resets it. The castles, soldiers and hero portraits use free CC0 art packs by Kenney and the sounds are made in the browser with the Web Audio API.

Where to start

Open Isleborn Kingdoms, claim your first daily chest, research Crop Rotation, and take the meadows next to your castle before you press End turn. If you like planning a few moves ahead, try chess and Tower Defense next, or browse the games hub.