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Tennis rules for beginners: serving, lets and calling the lines

Tennis · 6 min read · Updated August 2026

Scoring is one thing and the rules of play are another. These are the rules that actually come up on a public court, and they follow the ITF Rules of Tennis. Where a rule exists only because nobody is umpiring, it comes from The Code in the USTA Friend at Court, which is how players are expected to officiate themselves.

The court, and which lines are yours

Singles and doubles are played on the same court. The only difference is the two narrow lanes down each side, called the tramlines or alleys.

• The service boxes are the same size in singles and doubles. The alleys are never in play on a serve.
• A ball that touches any part of a line is in. That includes the faintest clip of the outside edge.

The serve

• You get two attempts at every point. Miss both and you lose the point. That is a double fault.
• Serve from behind the baseline, between the centre mark and the singles or doubles sideline, diagonally into the service box opposite.
• You start each game on the right and alternate sides after every point.
• Touching the baseline or the court with either foot before you strike the ball is a foot fault, and it costs you that serve.
• Serving underarm is perfectly legal. No rule requires you to throw the ball up.

A let and a fault are not the same thing

This is the rule people get wrong most often, and it usually costs somebody a point.

If your serve clips the net and still lands in the correct service box, it is a let. The point is replayed and it does not use up a serve. If it was your first serve, you still have two. If it clips the net and lands anywhere else, it is an ordinary fault.

• A let is replayed and costs nothing.
• A fault uses one of your two serves.
• A point is also replayed as a let if something genuinely interferes, such as a ball rolling on from the next court.

Worth knowing if you also play pickleball

Tennis still replays a serve that clips the net. Pickleball removed its service let in 2021, so a net-clipping serve there is simply live. Two sports, two answers, and the same players arguing about it on a Saturday.

Calling the lines when nobody is umpiring

Almost every match you play has no official, so The Code decides how calls are made. It is simpler than most players think.

• You call the balls on your own side of the net. Your opponent calls theirs.
• If you are not certain a ball was out, it is good. Doubt goes to your opponent, never to you.
• You may not call a ball out on your opponent's side, however clearly you think you saw it.
• Call out promptly and audibly. A late call is a lost argument.
• If you genuinely cannot agree and neither side is sure, replay the point.

When you change ends

• After the first game of every set, then after every odd game: the third, fifth, seventh and so on.
• At the end of a set, only if the total number of games in it was odd.
• In a tiebreak, every six points, and again when the tiebreak finishes.

Doubles, in one paragraph

Your team decides who serves first, and that order is fixed for the set. The receiving order is fixed too, so each of you always receives in the same box. Once the ball is in play either of you can hit it, and where you stand is up to you.

Common questions

Is a ball on the line in or out?

In. A ball touching any part of the line is good, down to the outside edge.

How many serves do I get?

Two. A let does not use one up, so a first serve that clips the net and lands in leaves you with two attempts still.

Can I serve underarm?

Yes. The rules say nothing about how the ball has to be struck, only where it has to land.

What if we disagree about a call?

Each side calls its own lines, and if you are not sure, the ball is good. If neither side is certain, replay the point rather than argue it out.

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