Sandtris Strategy: Wall-to-Wall Clears and the x2 Bonus

This guide covers the parts of Sandtris that decide your score: what counts as a clear, how points are worked out, the x2 bonus, and the two helper buttons in the right-hand column. Everything here comes from reading the game's own code and its three tutorial screens.

What actually clears

Sandtris does not clear rows. It clears connected patches of one colour. After a block lands and turns to sand, the game keeps checking the field for groups of same-coloured grains that touch each other side by side or above and below (diagonal contact does not join two patches). A group is removed when it reaches both the left wall and the right wall and holds more than 99 grains.

When that happens, the whole group goes at once, not just one line through it. The grains flash white, jump up a little and fall out of the field, and the sand above them drops into the gap. A thick band of green that touches both walls is cleared in full, together with any green that is joined to it.

How points are counted

Points come from clears. A clear is worth a quarter of the number of grains it removes, so a big patch scores far more than a thin strip that only just reaches both walls. The tutorial says the same thing in its own words: more collected horizontal lines of the same colour, more points.

That gives the main strategy. You do not have to hurry to clear a colour the moment it touches both walls, but letting a colour build up as one thick, joined layer before it connects pays more than lots of thin bridges.

The x2 bonus

If a clear happens within 15 seconds of the previous one, its points are doubled and an "x2" label floats up from the field. The timer starts again with every clear, so a steady run of clears keeps the bonus going. Two practical ways to use it:

• Keep a second colour nearly finished, one block short of touching the far wall, while you complete the first. Then close it inside the 15 seconds.
• Remember that a clear drops the sand above it. If a colour is waiting just above a patch you are about to clear, the drop can join it up and set off the next clear on its own.

Which colours you will see

There are four sand colours: green, yellow, red and cyan. The game opens them up slowly. Until you have made your first clear, new blocks are only green or cyan. Once you have cleared at least one patch, red joins them, and after three clears all four colours appear. The count is saved in the browser, so this only happens on your first sessions. Fewer colours make early clears easy, and the jump to four is when planning starts to matter.

Skip and Clear

The right-hand column shows the Next block and two buttons under it.

Button	What it does
Skip	Throws away the current block and brings in the next one. The tutorial uses it for blocks whose colour does not match your layers. The first two skips are free. After that the button shows an ad icon, because on Poki each further skip asks you to watch a rewarded ad. It also has a short cooldown (1.2 seconds), and in Classic mode it only works before you drop the block.
Clear	Always shows an ad icon (on Poki it is tied to a rewarded ad). It removes every grain of one colour that is on the field, picked at random, and scores it like a normal clear.

Use Skip when the next block's colour would bury a layer you are building. Save Clear for when the sand is close to the top, because you cannot choose which colour it takes.

How a game ends

The game is over when the sand reaches the top of the field. The game-over screen shows your score, and a crown appears when you set a new best. Classic and Speeding keep separate best scores.