The Coiling Technique: How to Trap Snakes in Slither.io

Coiling means wrapping your body around another snake so it has nowhere to go but into you. It works the same way in Slither.io and in Snake.io by Kooapps, the arena that plays on this site, because both games share one rule: a snake is knocked out when its head touches another snake's body. The game's own tutorial puts it in one line: "Make other snakes crash into your body to KO them." The CrazyGames page for Snake.io adds a matching tip: trap other snakes in a circle when you get big enough.

Why length comes first

A circle can only be as big as your body is long. A short snake cannot close a loop around anything, and if it tries, the target simply slips out through the gap between head and tail. Coiling is a move for the middle and late part of a round. Before that, your time is better spent eating pellets and staying clear of bigger snakes.

Picking a target

• Smaller than you. A snake that is much shorter has a smaller body to block you with, and needs less room to be trapped.
• Busy. A snake that is weaving through a cluster of pellets is watching the food, not your body.
• Away from other big snakes. While you circle, your whole body is spread out. A third snake can cut across your head while you are focused on the loop.

Closing the loop

1. Come up alongside the target rather than head-on, so your body runs parallel to it.
2. Curve your path ahead of its head and keep turning in the same direction. With mouse control your snake follows the pointer, so draw the circle with the cursor around the target; with keyboard control (arrow keys or WASD, picked in the tutorial or Settings) hold one turn direction.
3. Bring your head round toward your own tail. The aim is a ring with no gap the target's head can fit through.
4. Tighten slowly. As the ring shrinks, the trapped snake runs out of room to turn and its head meets your body.

When it crashes, the snake leaves its food behind (CrazyGames describes this as "all the food for you to munch on"). The pellets end up inside or near your ring, so you are already in place to collect them.

Where it goes wrong

• Boosting to close the gap. Holding the mouse button or Space speeds you up, but the game's tutorial says boost comes "at the cost of your length". Spending length to finish a ring makes the ring smaller and weaker.
• Losing track of your own head. While you watch the target, another snake may cross in front of you. Glance at the space ahead of your head between turns.
• Leaving the trap open too long. A gap that stays open lets the target leave, and gives other snakes a way in to steal the food.

Using a coil to defend

The same shape helps when you are the one under pressure. If a smaller, faster snake keeps darting at your head, curling your body into a tight spiral leaves very little open space near your head for it to aim at. Wait until it moves off, then unwind and carry on eating.