Start with pairs and separated matches
Scan every row for 00 or 11. A blank directly beside that pair must take the opposite value, because adding the same value would create an illegal group of three. Then look for a sandwich pattern such as 0 _ 0 or 1 _ 1. The middle blank also takes the opposite value. Repeat the same scan down every column before doing anything more complicated.
After each placement, scan again. One correct value can complete a new pair in its row and reveal another move in its column. This short chain reaction is the main reason a small board can be solved smoothly without guessing.
Use the three-of-each limit
Count the known values in any line that is at least half full. Once a row already contains three zeros, all remaining blanks in that row must be ones. The reverse is equally useful. Apply the same check to columns, and recount after every short chain of placements.
Do not wait until a line has only one blank. On a 6x6 grid, reaching the quota early can fill two or even three cells at once. If a tentative move would create a fourth zero or fourth one, it cannot be correct.
Compare nearly completed rows and columns
The uniqueness rule becomes useful near the finish. Suppose one completed row reads 0 1 0 1 1 0 and another row has the same known values with one blank. That blank must keep the second row different while still respecting balance and the no-three rule. Compare columns in exactly the same way.
Use uniqueness as a confirmation tool, not as your first scan. Pairs and balance usually produce the quickest moves; line comparison resolves the cells that remain after those easier deductions are exhausted.
Print a 6x6 binary puzzle for paper practice
Choose a difficulty in the game, then select Print. The printable version uses the original clue pattern instead of your current entries, so you receive a clean puzzle with space for a name, date, and solve time. The three rules are included on the sheet for quick reference.
On paper, write lightly until a value is fully proved. A small dot beside a row can remind you that it has already reached three zeros or three ones. When the grid is complete, check balance first, scan for triples second, and compare all six rows and columns last.
A reliable 6x6 solving loop is simple: scan pairs, count to three, compare lines, and repeat after every move. Once that sequence feels automatic, move to the 8x8 page for longer deduction chains.