Glossary
Molly
In one line: An ability that leaves a damaging area on the ground for a limited time.
What it means
Molly (from molotov) is the common name for every ability that creates a damage zone on the ground: fire, acid, ongoing blasts. Anyone standing in it loses health fast, so they have to move.
It has three main uses: flushing an enemy out of a corner, blocking a passage for a few seconds and, above all, stopping a spike defuse (denial). A random molly does little; a molly thrown where someone definitely is, or must be, can win a round.
An example
A defender is crouched behind a box in the corner, where they almost always sit. Instead of challenging them, you throw a molly behind the box: they have to come out, and when they do, you take them.