Block puzzle strategy: scoring, combos and keeping room
A block puzzle looks like a game about fitting shapes, but big scores come from timing. In Pebble Blocks you drag pieces from a tray of three onto an 8 by 8 board. A full row or column clears, and the game ends when none of your pieces fits anywhere. Here is exactly where the points come from, with numbers, and the habits that keep the board open long enough to collect them.
How scoring works
Every stone you place scores 1 point. A cleared line scores 10 points for each of its 8 stones, so a single row or column is worth 80. Lines cleared by the same move are weighted 1, 2, 3 and so on: two lines at once score 240 and three score about 480. When a row and a column cross, they share a stone that only counts once, so a cross scores 225.
Then comes the combo. Clear on consecutive moves and each clear is multiplied by the combo number: the first clear counts once, the next twice, then three times. A combo survives up to two moves without a clear; a third move without one ends it. Finally, emptying the board earns 300 bonus points, as long as at least 10 stones were on it before the move.
Here is a short run that starts with no combo:
| Move | What happens | Clear points |
|---|---|---|
| 1 | One row clears | 80 |
| 2 | A piece goes down, nothing clears, the combo holds | 0 |
| 3 | One column clears, combo ×2 | 160 |
| 4 | Two rows clear together, combo ×3 | 720 |
| 5 to 7 | Three moves without a clear end the combo | 0 |
Those four lines earned 960 points, plus the stones. Cleared one at a time with long gaps between them, the same four lines would have earned 320.
Why steady clears beat big ones
At the start of a run, two lines in one move and two lines on two moves in a row are worth the same: 240 either way, as 80 and then 160. The difference is what comes next. After two separate clears, your next clear is multiplied by three; after the single double clear, only by two. And once a combo is running, a multi-line clear is multiplied too: at ×3, a double is worth 720.
So aim for a clear every move or two, and save big clears for when a combo is already going. Keep a few lines one or two stones short of full, so that almost any tray holds a finisher. A combo needs a clear at least every third move, roughly one per tray.
Plan all three pieces first
A new tray arrives only when all three pieces are down, and you can't skip one. So before your first move, check that there is an order in which all three fit. Pieces can't be rotated, which is why a corner facing left and a corner facing right count as different shapes among the 37 the game deals. Shapes made of squares joined edge to edge are called polyominoes, and pieces that may not be turned are known as fixed polyominoes; our guide to polyominoes and block puzzles has their story.
Place the awkward piece first, while there is room for it: the 3 by 3 square, the five-long bars, the 2 by 3 rectangles and the big 3 by 3 corners. Save the single stone and the two-long bars for last, because they fit almost anywhere. And look for a first move that clears a line, since it may open room for the other two.
A faded piece fits nowhere on the board as it stands. Use the other pieces to clear space for it, because once it is the last piece in the tray and still fits nowhere, the game is over.
Keep the middle open
Where your stones sit matters more than how many there are. The 3 by 3 square needs an empty 3 by 3 area, and an 8 by 8 board has 36 places where one could go. Four stones in the right spots fill every one of them: put them where rows 3 and 6 cross columns 3 and 6, and the square has nowhere to land. That is the only arrangement of four stones that does it, and no three stones can. Push the same four stones into a corner and 32 of the 36 places stay open.
Long bars have the same weak spot. Any five cells side by side in a row of eight include the row's two middle cells, columns 4 and 5. So a single stone in either of those cells rules out every five-long bar along that row, and a stone in row 4 or 5 does the same for upright bars in its column. Build from the edges and corners inwards, and keep stones out of the middle unless they finish a line.
Never leave single holes
A hole is an empty cell boxed in on every side by stones or the edge of the board. Only the single stone can fill it, and the single stone turns up less often than most pieces. A gap one cell wide and two long is nearly as bad: it needs a two-long bar facing exactly the right way, or two single stones. Before you let go of a piece, look at its shadow and at the cells around it, and pick a spot that seals nothing off.
Set up crossing lines
A row and a column that are both missing the cell where they cross can clear together with one small piece, worth 225 points from a single move. A common setup: the bottom row is full except its last cell, and the right-hand column is full except its bottom two cells. An upright two-long bar dropped into that corner finishes both. Bigger pieces can finish more: the 3 by 3 square can complete three rows and three columns at once if you have prepared them.
Watch the fill level
How full is too full? We had a simple computer player, one that takes any clear it can, avoids holes and keeps its pieces against the edges and other stones, play 600 games with the game's own rules and piece dealer, and checked the board whenever a new tray arrived. Below 20 stones, the 3 by 3 square nearly always had room. At 20 to 23 stones it had room about nine times in ten, at 24 to 27 about three times in four, and at 28 to 31 only half the time. At 32 to 35 stones, half the board, it fitted only about one time in four, and at 36 to 39 one time in ten. Trays also began to arrive holding a piece that fit nowhere: about one tray in seven at 32 to 35 stones and nearly one in three at 36 to 39. A typical game ended with about 35 stones on the board.
Our rules of thumb follow from that. Below about 20 stones, build ready lines freely. From about 24, make every tray clear something. Past 32, stop building and clear before you add. Big pieces turn up more often as your score grows, so the same fill level is riskier late in a game. The game is a little kind: before dealing, it tries many random sets, prefers one whose pieces can all be placed and leans towards sets that allow a clear on a crowded board. Treat that as a cushion, not a plan.
The continue and the daily challenge
Once per game, when nothing fits, you can keep going: the two fullest rows and the two fullest columns are cleared and play carries on, after a short video where the game offers one. After using it, play more safely than before.
In the daily challenge everyone gets the same pieces in the same order. Your best score of the day is the one that counts, and playing on consecutive days builds a streak. Because the pieces are fixed for everyone, the daily can't pick sets to suit your board, so the habits above matter even more. The order also stays the same all day, which makes a second attempt a chance to plan for pieces you now know are coming.