A flick is a specialized technique in the MS ruleset of Chip's Challenge, which allows Chip to move a block off a Chip-acting wall. In many cases, it is otherwise impossible to get a block to its destination.
For a flick to work, the block must be directly next to Chip, on top of any Chip-acting wall from his current location. Some tiles, such as an ice corner or a thin wall, will only block specific directions. Also importantly, the block itself must be able to make the intended move legally; otherwise, nothing will happen.
In this small level, to reach the exit, Chip must move the block to pass the water. When he tries to move L (which would be expressed as -L in directional notation), the block is pushed L off the east thin wall, such that this happens:
and the block continues to slide across the ice until Chip can use it. Note that if the thin wall was facing west, the flick would not work from this direction, as there is no Chip-acting wall.
The Mouse Panel Glitch will perform a flick, and it is typically used for this purpose. Prominent flick levels include Captured, Switch Hit, Checkerboard II and Debug File, which all depend on the flick for the purposes of completing the level. Switch Hit and Checkerboard II are playable in Lynx, but the flick does not work in this mode; because of this, the former will require some trickery to be completed, and the latter is unsolvable by any other means; Debug File and Captured are not playable for other reasons.