Death is one of the main aspects of Happy Wheels. As in real life, dead characters cannot move without the aid of other objects or make sounds (with the exception of breaking bones and splattering bodies). Death can be caused in a variety of ways:
- Decapitation or complete destruction of the head
- Crushed by a meteor or any dense object.
- Torn in half or the pelvis being destroyed. (characters bleed out for 5 seconds after being torn in half and they die afterwards)
- Falling from a great height.
- Shredded by Lawnmower Man's lawnmower or Helicopter Man's helicopter blades.
- Stabbed in the head by spikes, blades or shards of glass (glass shards have to be big to kill).
- Sometimes, when you go up off the screen with great speed, you die and you return in pieces.
- Being smashed into a wall, "ceiling," or fixed object at excessive speeds.
- A blade weapon getting stuck through your torso, putting on so much pressure that it tears you in half.
- Falling down off of the screen.
- Getting blown up by an explosive.
Hazards are what mainly cause death. The arrow gun, harpoon gun, and spike set kill the character if they get stabbed through the head (for the arrow gun the arrow needs to penetrate deep into the head to kill the character). The landmine and homing mine blow the character to pieces. The wrecking ball smashes the character to pieces when a huge amount of force is exerted (although sometimes it may harmlessly knock the character away without killing them).
Some miscellaneous items will also cause death, including the blade weapon and the glass panel, which can kill the character if they are stabbed in the head (if the level maker allows it). The van and the meteor can crush the character, even without falling from a great height. The smaller miscellaneous items can also cause death, but only when a lot are placed in a level and fall a long way, or are launched at an extremely high speed at the character.
Lawnmower Man and Helicopter Man are the only characters whose vehicles can cause death on purpose, apart from crushing other characters. The lawnmower can shred people up and might leave some body parts lying around, while the helicopter can cut and stab people with its propellers. Other vehicles can cause death, but only when a character gets their head crushed; when they end up being stuck upside-down; or when they crush an NPC after falling a long way. Some heavier vehicles can also crush the chest by simply driving over it.
Dead characters are generally far more flexible than their alive counterparts, and will be able to rest in poses a breathing character would probably not be comfortable being in without being forced to.
- When a character falls from the bottom of the screen, they are not actually seen to die, but they simply become fixed and non-collidable, as if they had fallen into a giant hole in the ground. This is proven with Helicopter Man, as if the magnet or the helicopter goes down the bottom of the level but flies back up, the magnet (and anything attached to it), the helicopter, or parts of Helicopter Man will be uncollidable and turning off the magnet or ejecting will make some items fixed. It is hidden, but there is an invisible floor down there, that can be seen by playing Happy Green Hills as Irresponsible Dad and dropping the child under the bridge in the cave or Irresponsible Mom and dropping one of her kids. Sometimes, there is blood spurting on the map after you fall.
- NPCs do not die 5 seconds after being torn in half nor after losing their pelvis, and will continue to make sounds until they get blown into pieces, stabbed in the head, or killed by any of the scenarios mentioned above.
- It is rare to see an NPC's intestines. They also seem to lack tendons and spines.
- You can rarely survive under the screen but if you do not come up right away you die/disappear.
- In most levels, you must be alive to win, however, the primary and secondary characters' limbs can collect tokens.
- The character does not have to be alive to win when activating a victory trigger.
- Characters will often scream as they die, but their voice will immediately stop once dead.
- Unlike in most games, the level will not automatically end when the main character dies, instead the player must select the "exit game" option in the pause menu.
- Lawnmower Man does not actually kill an NPC when sucking one up into the lawnmower, unless you hear their head decapitate or explode when inside.
- In the mobile version, when the main character is torn in half, the edges of the screen turn red and start fading in and out; the sound of a heart beating will also be heard. This continues until the character bleeds out and dies.
- In the mobile version, the timer stops when the main character dies.