In Slither.io, there are many gameplay mechanics and strategies. Some are dangerous, while others can benefit you. Here are the instutios!
Gameplay Mechanics
"The Edge"
In all of Slither.io, there is no gameplay mechanic more annoying than the edge of the map, or Barrier. A common event that happens in Slither.io is you may lag out when you are close to the edge, resulting in you to slam into it. And unlike its predecessor, Agar.io, when you hit the wall, you do not slide alongside it. Instead, you disintegrate, your mass disappearing (unlike running into a snake), and restarting you back to the bottom.

You can work the edge to your advantage by cornering someone until they die, but that will be very hard as you may slam into the edge yourself.
Speeding Up
If you press the SPACE bar and/or hold the mouse (left and right mouse buttons are the same) and/or pressing the UP ARROW key, you will be able to go faster (while losing mass at a rate of 15/second). This may surprise an opponent you are hunting, and while the enemy is shocked, you can speed in front of them, killing them, and taking their mass. You will leave a trail of pellets behind according to your color of your snake-worm. Don't get too excited when speeding up! They can sideswipe you and kill you in seconds!
Mass Rushes
While this isn't an "official" gameplay mechanic, it is a very common event. Here is how it works:

Fun Fact: Mass Rushes are sometimes known as food riots or killing sprees, because so many snakes die.
The North
The North is infamous as a place where many of the leaderboarders hang out. The snakes are usually huge in size and mass and are experienced at the game, so don't go there unless you are sure you can kill them or avoid them long enough to wait for one of them to die.