Guide — Claymark

Claymark is a free browser tennis game — one clay court in golden-hour light, one tiebreak against an AI opponent, and a court that remembers every bounce and slide of the rally. This guide covers how to play, what the controls do, and how everything works.

What is Claymark?

Claymark is an arcade-style tennis match that runs in your browser. There is one court — a warm red clay court under late-afternoon sun — and one format: a tiebreak, first to seven points, win by two. You play against an AI opponent that reacts to your shots and tries to make you run. There is no install, no login, no account, and no download. The court itself accumulates the history of the rally — every bounce leaves a mark that fades slowly, so by match point the baseline is visibly scarred from the shots that landed there.

At the end of the match you get a mark map: a top-down view of the court showing every bounce and slide scar the rally actually produced, with your scoreline and longest rally. That is the thing to share.

How to play

Desktop (recommended). Claymark is built for a keyboard and mouse. The player auto-positions toward the ball — you own timing, direction, and spin.

• Move your mouse to aim. A subtle indicator on the court shows where your shot will land.
• Hold the left mouse button to load power. A power arc fills over about 0.8 seconds. Release to swing.
• Hold Shift for topspin — the ball dips hard and kicks forward on the bounce.
• Hold Ctrl for slice — the ball stays low and skids sideways.
• No modifier = a flat shot — fastest, least curve.
• W / S or scroll fine-tunes your aim depth.
• The serve is a timing minigame: press and hold to toss the ball, release when it reaches the peak of the toss to swing. Release too early and it hits the net; too late and it sails long.
• R = instant rematch from the results screen.
• ` (backtick) toggles the debug overlay, which shows ball speed, spin, AI state, and the tuning constants.

Mobile. Claymark runs on phones at a reduced graphical tier — fewer dust particles, lower shadow resolution, simpler fence — and uses touch controls. Drag on the lower half of the screen to aim; the direction and length of your drag set direction and depth. Two buttons below the court let you pick topspin or slice; without a button pressed, your shot is flat. Power fills automatically as the opponent's return travels toward you; release your drag to swing at the current power level.

Claymark is built for a desktop and a keyboard. On a phone it works. It is not the same game.

Spin types — what they do

Spin is what makes tennis feel like tennis, and Claymark models three distinct shot types. The ball trail changes colour to show you what spin is on the ball — warm gold for topspin, cooler white for slice.

• Topspin (Shift). The ball rotates forward (topspin). In flight the Magnus effect pulls it downward, so it dips faster than a flat shot and bounces higher. On landing, topspin converts to forward kick — the ball accelerates off the court. Use it to hit hard and deep without sailing long. On clay, topspin is the defining shot.
• Slice (Ctrl). The ball rotates backward and sideways. The Magnus effect keeps it flatter in the air, and on landing it skids low and sideways. Use it to change pace, wrong-foot the opponent, or approach the net.
• Flat (no modifier). Pure pace, no spin. The fastest shot but the least forgiving — it does not dip, so you must aim lower over the net. On clay, a flat shot sits up more than on hard court.

How the tiebreak works

A tiebreak is a short game played to decide a set when the score reaches 6–6. In Claymark, every match is a single tiebreak: first to 7 points, win by 2. The server changes every two points. You serve from behind the baseline; two missed serves (faults) in a row is a double fault and hands the point to the opponent. The score is displayed as server first — so "6–4" means the server has six points and the receiver has four. If it reaches 6–6, play continues until one player leads by two.

A typical tiebreak takes 3–5 minutes. The natural next action is "rematch" — and the rematch button is the loudest control on the results screen.

The court — it remembers

The clay court is not just a flat rectangle. An offscreen buffer records every ball bounce as a mark on the surface — fresh marks are lighter than the court (disturbed clay catching the light), and over about three seconds they darken and fade (compressed, settled clay). By match point the baseline carries visible scarring from every shot that landed there. At match end, a top-down render of the court — the mark map — shows all those marks with the scoreline and longest rally. No two matches produce the same mark map.

How the AI opponent works

The AI opponent is governed by exactly three numbers, all in one tuning file:

• Reaction delay — how long the AI waits after your shot before it starts moving. A longer delay means you can wrong-foot it; a shorter delay means it reads you instantly.
• Top speed — how fast the AI can run laterally. Higher speed covers wide angles; lower speed means wide shots are winners.
• Error radius — how precisely the AI aims. A larger radius means it misses more often.

Those three numbers define three difficulty tiers you can pick from the results screen — Casual, Standard, and Sharp. Casual reacts slowly and mis-hits the wide ball; Standard is the baseline club-player opponent; Sharp reads your shot fast, covers the wide angles, and rarely misses. Your choice is saved and applies to the next match. There is no machine learning and no "levels" — the AI is a pursuit controller plus a weighted shot-zone picker that tries to hit away from where you are standing. Press the backtick key during play to see the three numbers live in the debug overlay.

The daily leaderboard

After each match, your longest rally from that match is sent to a daily board — but only if you beat your personal best. You are represented by a two-word handle generated from a word list (like "Feral Heron"). No text you type ever leaves your browser. The board resets each day at midnight UTC. Reroll your handle anytime from the results screen. The board is for fun; stats are reported by your browser and we do not verify them.

FAQ

Is it free? Yes. Claymark is free to play, supported by ads. There is no premium tier, no subscription, no account, and nothing to buy.

Do I need an account? No. There is no login and no sign-up. Your wins, losses, and longest rally are saved in your browser.

Can I play offline? Yes. The game runs entirely in your browser. The daily leaderboard and the mark-map share link need the network, but the match itself does not.

Why does it look different on my phone? Claymark adjusts its graphics for your device. On a phone it runs at a reduced tier with fewer particles and lower shadow resolution. It is playable but designed for desktop.

What is the mark map? After each match, Claymark renders a top-down image of the court showing every bounce mark and slide scar the rally produced, with the score and your longest rally. It is a PNG you can share — every match produces a different one.

Does the AI cheat? No. The AI plays by the same physics you do. It has a reaction delay, a top speed, and an aim error — all visible in the debug overlay (press the backtick key). It never teleports and never sees the future.