What is Curse?

[Gngrman]

I just started playing this and enjoy it. I see people open tables with "Curse On." What does that mean? How does it affect game play. I already have enough challenges with fire lol.

[Zmajoubica]

The Curse
An Optional Variant
If three tiles of the same number form a mini-pyramid (two of the tiles next to each
other, one on top of them), either via placement or after resolving mayhem, the
curse is activated. The three tiles are removed and go under the draw pile of the
previous player. Any tiles coming off the pyramid from follow-on collapses and
other mayhem also go under the draw pile of the previous player. That player
decides the direction any tiles fall after follow-on collapses.
Only check for the curse after checking for collapses, explosions, and fires.