"Player" was squished

—Death message

Falling Spikes are giant metal spikes in Quake that come out of the ceiling to injure the player. These can kill enemies also, but it is a dangerous risk to try to lure them under the spike. The Falling Spike can start when the player gets close, or can continually slide up and down. The Falling Spike also varies with damage, with some taking 40% of the player's health and others killing the player in one hit, even with Armor.

In E1M3: the Necropolis, there is a spike that is fired out of its base towards the player called the Shooting Spike. It is the only type of spike that can come out of its base. Unlike the Falling Spike, the Shooting Spike cannot injure the player by itself. Instead, it relies on its faster speed to push the player against the wall it is aiming for, which can injure the player by 49 health points.

In E1M5: Gloom Keep, there are Falling Spikes that are vertical, or on the walls to the sides of a platform. As they do not fall, and instead slide in and out, they are Sliding Spikes. Unlike the regular Falling Spike, a Sliding Spike cannot injure the player. Instead it attempts to push the player off the platform they are standing on. Perhaps it would injure the player by 4 health points if the opposite side wall was close enough to be hit by the player when the Sliding Spike was fully extended, but as no example is shown, it is but a hypothesis based on the game mechanics.

In Shub-Niggurath's Pit, there is a horizontal Falling Spike that is thinner than the Sliding Spike. As this type of Spike does not have a base, they are Hidden Spikes. They are even faster than the Shooting Spike, and thus can be extremely lethal due to the close proximity the player finds them in. It takes the player down thirty health each time it hits the player. If the player knows where the Spike is, they can simply jump over the area where it would come out.