How Slot Symbols Are Designed: From Paytable Hierarchy to Art Brief

The cherries, bars and lucky sevens on a classic machine were not chosen for beauty. Cherries were fruit-gum flavours on the Bell-Fruit machines of the 1900s, the BAR was the logo of the Bell-Fruit Gum Company, and the seven was borrowed from dice and card games. Slot machine symbols have always been a system first and pictures second. A hundred years later the symbols on a 5×3 video slot follow rules that are just as strict — they are only better hidden.

This is how a symbol set is designed at a studio: from the paytable hierarchy, through readability, to the art brief.

The hierarchy comes before the drawing

Every slot symbol set is a ladder with four to six rungs. At the bottom sit the low symbols — historically card ranks (10, J, Q, K, A), today often themed objects — which appear most often and pay least. Above them the mid and high symbols, usually four or five characters or artefacts that carry the theme. At the top the premium symbol, which pays ten to twenty-five times more than a low symbol. Beside the ladder live the functional symbols: wild, scatter, bonus, collect, multiplier.

The paytable decides the order; the art has to make that order visible in a tenth of a second. A player scanning a spinning reel should know, without reading the paytable, that the crowned king is worth more than the goblet and the goblet more than the ten. This is why premium symbols are larger in visual mass, warmer, more detailed and often animated, and why card ranks are flat, cool and quiet.

Readability at 120 pixels

On a phone in portrait a symbol is 100–140 pixels wide and it is seen for a fraction of a second while the reel moves. Three practical rules follow:

• One silhouette per symbol. If two symbols share an outline (two round coins, two square gems), players confuse them during the spin and the win presentation feels arbitrary.
• One dominant colour per symbol. Colour is the fastest signal. A set that uses gold for the king, red for the apple, blue for the goblet and green for the harp is scannable; a set where everything is gold is not.
• Value in the centre. Detail concentrates in the middle third of the tile; edges stay calm so that neighbouring symbols do not blend into each other.

We test every set with a blur pass — a screenshot of the reels blurred to the point where only mass and colour remain. If the hierarchy still reads, the set works.

Classic slot machine symbols and why they still matter

Fruit, bars and sevens carry meaning that took decades to build: a red seven means “top prize” to players who have never read a paytable. Modern studios borrow this in two ways. Retro-neon games such as our own Neon Cash use the classic set almost directly, relying on that inherited meaning. Themed games keep the structure and swap the objects — the seven becomes a crown, the bar becomes a golden bar. Either way, the player’s expectation of “which one is the big one” is inherited, not taught.

The functional symbols

Wild substitutes for paying symbols. Its art must say “anything” — a mask, a burst, a logo — and must look different from every paying symbol even when expanded across a reel. Scatter triggers features from any position; players learn to spot it during the spin, so it must be the most contrasting symbol on the reels and is usually the only one allowed a glow or an animated idle. Collect, multiplier and money symbols in hold-and-win mechanics carry a number, which means a readable numeral on a small tile — a design problem in itself.

Animation as a second layer of hierarchy

Symbols get animation budgets by tier. Lows: none or a subtle win pulse. Mids: a short win loop. Highs: a win loop with particles. Premium: a win loop, an idle when it lands, and a role in the big-win sequence. Wild and scatter: land animation, win animation, anticipation state. The budget is money — each animated symbol is a sprite sheet or a rigged character — so the design document lists it explicitly, and the art brief is priced from that list.

The art brief we hand to an illustrator

For each symbol: tier, pay for five-of-a-kind (so the artist understands its rank), one-line description, dominant colour, silhouette note, and animation level. Plus three global constraints: the tile size, the blur test, and a colour map of the whole set so no two symbols share a palette. A brief written this way produces a usable set on the first round; a brief that says “draw us ten Egyptian symbols” produces three rounds of revisions.

Symbol systems — hierarchy, palette, animation tiers — are the core of what our art team does for our own games and for clients. The scope is described under slot game art and animation, and the Midas Golden Era symbol set is a worked example on the same page.

Background reading (Japanese, German): the colour-hierarchy conventions of Japanese pachislot machines, and German coverage of the history of Frucht-Symbole on early Bell-Fruit machines.