Block Retrace Rule: Difference between revisions

no edit summary
imported>Octavarium64
(Creating page with: The '''Block Retrace Rule''' is a common principle of block pushing, used in many situations to minimize the wasted time turning blocks in several directions. To apply thi…)
 
No edit summary
 
(3 intermediate revisions by 3 users not shown)
Line 16: Line 16:
[[File:Block Retrace.png]]
[[File:Block Retrace.png]]


In this small [[Sokoban level]], Chip must move the three blocks to the three [[brown button]]s in order to pass the [[ice]] and [[trap]]s to the exit. Block 2 is directly used on button 3, as it is on the edge of the [[clone machine]]s. Following this, the rule can be used on the other two buttons. Move block 3 R, following the [[Block Donut Rule]], and push block 1 only 3U 4R, not 3U 4R D. The D move will be accomplished from a more advantageous position, U off the block rather than from L off, when block 3 is moved to button 1.
In this small [[Sokoban level]], Chip must move the two blocks to the two [[brown button]]s in order to pass the [[trap]]s to the exit. The rule can be applied as follows: move block 1 3R, instead of moving it 3R D onto trap button 2. The D move will be accomplished from a more advantageous position. Move block 2 2U 5R onto trap 1, then immediately move D to push block 1 from before into place. This rule saves two [[In-game second#Move|move]]s compared to the naive approach of focusing on only one block at a time.
 
Note that the above situation is another, more limited case of the rule, as the second button press is retraced in itself. It will use 2 moves in comparison to moving the block 3U 4R D immediately; most cases will not spend any extra moves at all.


[[Category:Mechanics]]
[[Category:Mechanics]]
[[Category:Terminology]]
[[Category:Terminology]]
[[Category:Principles of block pushing]]
[[Category:Player strategies]]