GemTD online

The game in a nutshell

A tower defense where towers are not placed along a ready-made road — you build the road yourself. The board is 17×17, creeps run from the entrance to the castle through six mandatory checkpoints, and every stone you place makes their path longer. Sealing the route off completely is not allowed: such a placement is simply rejected.

Each build round you place exactly five stones of random colour and quality, then keep one of them. The chosen stone becomes a tower; the other four stay in the maze as blank walls. Every round you gain a tower and ruin part of your own board at the same time — the only question is where to ruin it.

Ways to play

• Quick Match — matched with rivals; difficulty and match length are decided by everyone’s filters.
• Private room — your own match by link: invite friends and set the difficulty and wave count yourself.
• Versus AI — the same race against bots, so you can play alone as well.
• Spectating — anyone can watch a live match and switch between the boards.

Gems and merges

• Eight colours by six qualities make 48 base towers: damage, slow, poison, splash, cleave, armour reduction.
• Merges turn ordinary gems into 43 combo towers across 59 recipes.
• Plates trigger when a creep walks over them and upgrade by geometry: three of a kind in a line make the next rank.
• A prayer raises the chance of the colour or quality you need on the next stone — for gold.