OneTaskBy Tim King · Updated
Jenga Game Online
Pull Blocks From a Physics Tower Without Toppling It
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How the Jenga Game works
This Jenga game online is played with real block physics. A tower of wooden blocks stands on the floor, three to a layer. Drag a block out of the middle and set it on top, then do it again. Every block has real mass and friction, so the tower leans, slides and eventually falls exactly the way a wooden one does. The stats count your moves and the tower's current height; Stack again rebuilds it and Nudge gives it a random shove to see how stable your work is.
Jenga game online: getting a good result
The tower is a simplified side view of the tabletop game: alternate layers are laid across or along, so from the side you see either three narrow blocks or one wide one. The narrow-block layers are where you take from; the wide ones are what carries the load.
Why it falls. A stack stays up while its centre of mass is above the blocks it rests on. Pull a block from one side of a layer and the two remaining ones still support what is above, but the base of that layer is narrower; pull the middle one and the load runs down the two edge blocks, which is stable until something above shifts. The moment a layer's support lies to one side of the weight above it, the tower rotates, and once it starts it does not stop. The friction slider changes how much a block can slide before it goes: low friction makes pulling easy but the tower slips apart; high friction grips the blocks so pulling one out drags its neighbours.
Dragging. The mouse is a spring attached to the point you clicked, so a fast drag yanks the tower. Ease a block out slowly, the way you would with a real one, then lift it clear before moving it over the top. Dropping it from a height jolts the stack; lower it.
Layers and block length set the tower before the first move, and a taller tower is harder for the obvious reason: more weight above every gap. Blocks are density-matched wood, and the simulation uses the Matter.js rigid-body engine, so nothing here is scripted — the tower can fall from the first pull if you are careless, or stand for thirty moves. Pause, Fullscreen, Save PNG and Reset work as in the other physics toys.
FAQ
How do I pull a block out without toppling the tower?
Drag slowly. The mouse is a spring attached to where you clicked, so a fast drag yanks the whole stack. Ease the block out, lift it clear, move it over the top and lower it gently rather than dropping it.
Why does the tower fall after a move that looked safe?
A stack stays up while its centre of mass sits above the blocks supporting it. Removing a block narrows the base of that layer, and any later shift above it can move the weight past the edge. Once a layer starts to rotate it does not stop.
What does the friction slider do?
Low friction makes blocks easy to pull but lets the tower slip apart on its own. High friction grips the blocks together, so pulling one out tends to drag its neighbours with it. The default sits between the two.
What is Nudge for?
It gives the tower a random shove so you can test how stable your work is. A well-built tower sways and settles; a tower with too many gaps on one side goes over.
See also: all Simulations & Screensavers tools, Images, Audio, Video & Screen, PDF, SVG, Generative Art, Chart Makers, 3D Model Viewers, Drawing Pads, Mockups & 3D Making, Diagram Makers, 3D Science, Tracker Music.
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