Play Swap Siege online
Swap Siege is a merge-defense arcade game: swap adjacent tiles to fuse weapons, then hold the castle against 6 waves of dragons.
Every build phase gives you 8 swaps. Line up same-tier weapons — Sling, Bow, Cannon, Ballista — and they merge into a stronger one automatically.
When you send the wave, dragons stream in from the left and your weapons fire on their own. Each dragon that reaches the gate costs the castle a heart.
Survive all 6 waves with hearts to spare to win. Your best wave is saved locally.
How to control Swap Siege
- Swap: tap two adjacent tiles, or drag between them
- Space: send wave • R: restart • M: mute
How to play
- 1
Tap two adjacent tiles (or drag) to swap them — each swap costs 1 move.
- 2
Two adjacent weapons of the same tier merge into the next tier: Sling → Bow → Cannon → Ballista.
- 3
You get 8 moves per build phase. Press SEND WAVE (or Space) when ready.
- 4
Weapons auto-fire at dragons in range. Each dragon that reaches the gate costs 1 castle heart.
- 5
Survive all 6 waves to win. Your best wave is saved on your device.
Tips for a better run
Merge early and often: one tier-3 Cannon out-damages three tier-1 Slings for the same board space.
Swaps with empty cells still cost a move — plan your merges before spending moves on repositioning.
Weapons only hit dragons within ~2.6 tiles, so spread strong weapons across rows, not one column.
Dragons target random rows — keep at least one tier-2+ weapon covering the top and bottom rows.
Save your last 2 moves: the 3 free tier-1 reinforcements between waves can complete a merge you set up.
Frequently asked questions
How do I swap tiles?
Tap two adjacent tiles (or drag from one to a neighbor) to swap them. Every swap costs 1 move.
How do weapons merge?
Two orthogonally-adjacent weapons of the same tier merge into one weapon of the next tier (Sling → Bow → Cannon → Ballista). Merges cascade automatically.
How do I win?
Press SEND WAVE (or Space). Each wave you get 8 moves to merge. Survive all 6 dragon waves without the castle losing its 6 hearts to win.
Do I control the weapons during a wave?
Weapons fire on their own at dragons within range. Higher tiers hit much harder — a Ballista out-damages four Slings.
Is Swap Siege free?
Yes — it runs entirely in your browser with no downloads, no accounts, and no ads. Your best wave is saved locally on your device.
