Jace: the endless number puzzle that keeps getting harder

Most brain games have a finish line

You open a puzzle, solve it, see a score, close the tab. That shape works. It fits in ten minutes and gives you a number to compare against last week. It also sets a ceiling: once you know you can finish a level, the only question left is how quickly.

What changes when a game never ends

Jace has no final level. You drag a number onto a neighbour that differs by exactly one, the two merge, and new rows keep arriving from below. The faster you clear, the faster they come. Sooner or later the board fills up and the run is over.

So the difficulty stops being something the designer hands you on a schedule. Play well and the pressure rises. The reward for a good move is a harder position.

The decision it trains

Most of the time the move in front of you is not the interesting part. The choice is between a short safe merge now and a longer chain that clears more but leaves one column a tile taller. Both are defensible, and you usually find out which was right about three moves later.

That is ordinary planning. It is what you do loading a full dishwasher, or working out the order of your errands so one trip covers them all. Each decision looks fine on its own, and the cost only turns up when there is no room for the next thing.

Why the leaderboard is part of the game

A score with no ceiling does not mean much on its own, so Jace keeps three boards: today, this week, and all time. The daily board resets often enough that one good run still counts for something, while the all time board is where a really good run stays.

You can play without an account. You need one for a run to be saved and ranked, and if you sign in after a run, that run goes onto the board.

Give it a try

Jace is free for everyone, with no subscription and no daily limit. See how long you can keep the board clear: play Jace, or look through the rest of our brain games first.