Block Out Guide: How to Clear Color Stacks and Tubes

To prevent dead ends in intermediate levels of Block Out, your immediate goal is to empty one vertical tube as early as possible to use as a staging space. Once you open a tube, strip away matching upper color layers to expose deeply buried colors rather than shifting blocks back and forth across filled columns.

Why Opening an Empty Tube Comes First

An open column gives you a free buffer slot to move obstructing blocks out of the way without locking other stacks. Without an empty tube, sorting options shrink quickly, leading to situations where no legal moves remain.

When starting a new layout:

1. Scan the board for the column closest to being cleared.
2. Focus initial moves exclusively on stripping blocks out of that specific column.
3. Keep the cleared column empty whenever possible so it remains available as a temporary holding zone.

How to Peel Deep Color Stacks

The main hazard in intermediate puzzles is burying a color you need under mixed layers. Shift the topmost block of a cluttered stack into your empty tube or onto an existing stack of the same color.

Check the bottom-most color of your tallest columns. If the base color cannot merge with a matching destination, work from the top of that column downward to liberate the block. Shifting pieces without checking what lies beneath often traps critical colors under incompatible blocks, forcing a level restart.

Step-by-Step Priority Sequence

Follow this order of operations on every turn to keep your board organized:

1. Clear a destination match: Move a top block directly onto a matching color stack if space allows.
2. Open a buffer zone: Move single blocks into an empty tube to uncover different colors beneath them.
3. Consolidate columns: Shift matching color groups into a single tube once space opens up.
4. Target cluttered columns: Prioritize columns containing three or four different colors over columns that only hold two.

Reducing the height of your tallest, most mixed stacks keeps move paths open and prevents tight board states as puzzles grow more complex.