Digital Logic Design (The Game)

Somewhere between a logic textbook and a Cookie Clicker sits Digital Logic Design (The Game). asterisk_man built it in 2014, released it under GPL-3, and posed a question the genre rarely asks: what if the thing you automated was actual computer engineering? Your only primitive is a NAND gate. Everything else, from a simple NOT to a working adder, is something you design, verify and sell.

What the loop feels like

You start mining silicon by hand, because gates do not grow on trees. With a stockpile banked, you open a design contract, write a netlist wiring NANDs together until the truth table matches, and submit it to the simulator. It either passes or it does not, and when it passes, the sale pays cash that buys better mining and the next contract. That's Digital Logic Design (The Game).

A few contracts later the loop deepens. The gates you built become reusable blocks, so an XOR you refined once nests inside a multiplexer, which nests inside a register, and the designs stop being puzzles and start being architecture. Automation takes over the silicon while your attention shifts to whether a circuit can be shaved a gate or two thinner, because every physical gate costs silicon each production cycle and bloat eats your margins. That's Digital Logic Design (The Game).

The systems underneath

Everything rests on the NAND foundation: NOT, AND, OR and XOR cannot be spawned, only architected from interconnected NAND configurations. The silicon economy makes those gates physical, with early manual mining later replaced by automation upgrades. Designs are expressed as netlists defining ports, inputs, outputs and component instantiations, and an automated simulator verifies each one strictly against the truth-table requirements of the requested component before the market pays out, with efficiency scaling the reward. The tech tree marches upward from primitive gates through adders, multiplexers and registers to sequential logic, and cash funnels back into business upgrades for mining yields and passive income. Veteran advice is consistent: minimise gate count before mass production, keep a personal library of clean netlists as modular black boxes, and brush up on Boolean algebra, De Morgan's laws and Karnaugh maps before the mid-game asks for them.

Where it stumbles

The learning curve starts gentle and turns abrupt, ramping into dense Boolean translation without holding your hand. Documentation is thin where it matters most: players routinely trip on strict formatting quirks, such as port declaration ordering, where a tiny mismatch breaks the logic readout with little guidance on why. And the presentation is dry by any modern standard. This is a text-and-CSS project with no graphical circuit boards, which demands patience, paper for mapping, and a genuine tolerance for utilitarian UI.

Playing it today

The game remains free and requires no signup, running as pure HTML/JS directly in modern browsers: play it on GitHub Pages. The source is available under GPL-3-or-later at the project repository, and the community gathers on the game's own subreddit. For another silicon-flavoured loop, see Upload Simulator Silicon in this catalog.

The verdict

Digital Logic Design (The Game) is the rare incremental that could legitimately appear on a syllabus. The gates are real, the verification is real, and the satisfaction of watching a self-sustaining cash flow mine silicon while your circuits sell themselves is genuine. It is rough, dry and occasionally obtuse, and none of that matters if Boolean algebra sounds like a good time rather than a warning label. For its audience, it remains one of the genre's most rewarding oddities.