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 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 chalk ring on the court shows where your shot will land.
• Click or press Space to swing. One press is one swing — there is nothing to charge.
• Power comes from the ball, not a meter. The player runs to the landing point on its own; the closer you are to the ball when you swing, the harder the shot. The power arc in the HUD shows the strength your swing will carry.
• Let it bounce. You can only strike the ball after it has bounced on your side. There are no volleys.
• 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.
• The arrow keys aim too — hold left or right to move the target across the court, up or down to move it shorter or deeper. A held arrow key wins over the mouse, so hold it and click to place the ball exactly.
• The serve is a timing minigame: press and hold to toss the ball, release inside the gold band (the sweet spot near the top of the toss) to strike it. 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 the ball's speed and spin, the AI's state and target, and the tuning constants.

Mobile. A phone does not get a different game — the same court, the same physics — but it does get different controls, because there is no keyboard and no mouse. Tap the court where you want the ball to go: the tap is the swing, so you aim and strike in one motion and the chalk ring lands on your target. Two buttons below the court pick topspin or slice; with no button held, your shot is flat. Power is the same rule as on desktop — the closer you are to the ball when you tap, the harder you hit. And the bounce rule is the same too: tap before the ball has bounced on your side and nothing happens.

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, a cool white for slice, and a neutral cream for a flat shot.

• Topspin (hold Shift; the TOPSPIN button on a phone). The ball rotates forward. 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 (hold Ctrl; the SLICE button on a phone). 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 on every point — you serve the first point, the opponent serves the second, and it alternates from there. 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 shown with your points first — so "6–4" means you have six and the opponent 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. Claymark records a mark on the surface for every ball bounce, and every contact, and keeps the most recent hundred-odd of them drawn — fresh marks are lighter than the court (disturbed clay catching the light), and over about five seconds they darken toward the settled colour of compressed clay. By match point the baseline carries visible scarring from the shots that landed there. At match end, a top-down render of the court — the mark map — shows those bounces 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, or if that match changed your win–loss record. 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? It is the same court — the same renderer draws every device, with the same marks, the same light, the same colours. What changes is the shape of the window and the controls: a phone held upright is a tall, narrow viewport, and you play by tapping the court instead of moving a mouse. It is playable, and it is designed for desktop.

What is the mark map? After each match, Claymark renders a top-down image of the court showing every bounce 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.