0x03 Capture the flag

Play online. Earn your place in Dehradun.

The free, 36-hour qualifier runs on 17–18 February 2027. Play from anywhere, alone or with a team. Top qualifiers reach the on-site final on Saturday 3 April.

Online qualifier
17–18 February 2027 Free, open to anyone and played from wherever you are. No conference pass is needed. The start hour will be emailed to registered players.
On-site final
Saturday 3 April For the top qualifiers, in Dehradun. Each finalist needs a full conference pass or a ₹799 competitor pass.
Team size
Teams of one to four Playing solo is welcome. You can also ask us to introduce you to other players when you register.
Registration
Open, no ticket needed Submit the form below for the free online round. Pass details are optional and only matter if you reach the final.

3–4 April 2027 a Dehradun venue, to be announced Online round, then the final on day one

01 What it is

Built for first-timers and regulars alike.

Start with approachable challenges or chase the hardest flags. Our team tunes every online challenge on LevelUpCTF, then builds and runs the smaller final on site.

A wide view down a long line of white bench desks in a hall with a pale wooden floor, around twenty-five people working at laptops with headphones and phones beside them, teal and yellow chairs, taped cable runs across the floor and a green fire exit sign above double doors at the far end.
Players at an earlier BSides Dehradun CTF.
  1. Round one · 17–18 February 2027

    The online round

    Free, open to anyone who registers, played from wherever you are, and it runs for 36 hours. The hour it opens goes out with the programme and reaches the email on your registration.

  2. Shortly after

    Everyone hears the result

    Qualified or not, by email. The top qualifiers go through, and solves are checked by write-up and against each other before that list is fixed.

  3. Day one · Saturday 3 April

    The final, on site

    Qualifiers only, at a Dehradun venue, to be announced, on your own laptop. Workshops run the same day; the talks and the villages are on day two.

The online round runs on LevelUpCTF, our CTF partner. Our own team tunes every challenge it generates and sets the difficulty across easy, medium, hard and extreme. The smaller final on site is built and run by the team itself.

  • First time is a normal way to start

    Entry-level challenges give new players a place to start, without making the round a separate beginners' bracket. Say on the form it is your first CTF and we will point you toward them.

  • Arriving without a team is not a problem

    Tick the box on the form and we will pair you up before the online round, or at the CTF desk on the day.

Why the tuning matters

A challenge shipped exactly as it came off the platform is one somebody may already have seen, write-up and all. Reworking each is more work for the team and a fairer game in both rounds.

Not a player?

The villages are the other half of the hands-on programme: a table, a subject, and someone who will explain it forty times. Several are gentler than a CTF for a first weekend.

See the villages
A player in a cream hooded top leaning in close to a laptop with one hand at their glasses, and a line of desks receding behind them where six or seven more people work at laptops under concrete pillars.
Heads down on a challenge.
Two players sharing one long desk, the nearer one in a navy fleece with a laptop open on a terminal, the further one watching their screen, and a paper cup and a phone between them.
Two hours in, on the same problem.
One laptop from over the player's shoulder, a dark terminal filling the screen, with a second competitor at the next desk along and the hall out of focus behind.
One screen, close up.
A side table against a window wall, two people working on laptops with a third leaning over to look, daylight coming in behind them.
The side tables, by the window.

02 How to take part

From free qualifier to on-site final.

Register for the online round without buying a ticket. The scoreboard decides who reaches the final; a pass is only needed if you qualify.

  1. Register on this page

    Play solo, create a team or join one with a code from your captain. Each player registers so we can send them the round details.

  2. Play the online round

    On 17–18 February 2027, from wherever you are, over 36 hours. Free, and no ticket needed. The hour it opens is emailed to the address on your registration.

  3. If you qualify, pick how you get in

    The final is at the conference, so it needs a pass: a full conference pass, or the ₹799 competitor pass. Qualifying does not oblige you to buy the bigger one. Tickets are not on sale yet, and the tickets page carries the three full prices, which are set.

  4. Bring a laptop, and find the CTF desk

    The final is on day one. Assume contested wifi. Where the desk is and when it opens go out with the programme, and it is where to go if your team is a person short.

Format
TBA Categories and scoring are published with the programme.
Who reaches the final
The top qualifiers How many go through, where the line falls and the tie-break on it are published before the round opens, not after it closes.
Fair play
Checked by write-up submission and plagiarism checks Solves are verified before the qualifying list is fixed, so a flag that came from somewhere else does not take a seat from a team that earned it.
Prizes
TBA Dependent on sponsorship. We will not announce a prize we are not certain we can hand over.
Ask about it
[email protected]

03 Register

Register for the free online round.

Join on your own, create a team or use a code from your captain. You do not need a pass or ticket reference to register. We will email the start time and access details before the qualifier.

How are you playing?, required
Whoever fills this in is who we write to.
What you want on the scoreboard. Your own name or an alias that leads nowhere near it, either is fine. We do not check it.
Anything the CTF needs to tell you in advance goes here, the team code included if you are the captain.
Not the same thing as your handle. On your own, your handle is a fine answer. Joining, use the name your captain registered, and if the two do not match, the code decides.
The code your captain was emailed. Leave it empty if you are playing alone or creating the team. If you are joining without it, register anyway and say so in the last box.
One name per line, yourself included or not. Leave it empty if you are playing alone or still recruiting. The online round is free, and passes only come into it if the team reaches the final.
This helps us point first-time players toward a starting challenge. It does not affect scoring or qualification.
A team is one to four people, so 1 is a normal answer. Count yourself in it.
Leave this blank if you prefer. The online round is free; a pass is only needed if you qualify for the on-site final. What a pass costs.
Only if you answered yes above: the order or ticket ID from your confirmation email. We check it against the ticket list and store nothing else from your order.
Access requirements, a laptop you cannot bring, a category you have never touched and would like pointing at. Practical things. This is not a pitch.

This reaches the organising team through our site and email service. It is not a payment and does not confirm a ticket. How we handle your details.

Before you fill it in

Start hour to be confirmed
Registration is open. The online round runs for 36 hours on 17–18 February 2027, free, with no ticket involved until the final. The start hour reaches the email address you put on the form.

What we do with it

Form delivery
Cloudflare Pages handles the submission, then Resend emails it to the organising team. A platform account is not created instantly.
Platform setup
Your handle, team name and email address are used to set up online-round access with LevelUpCTF. Your experience answer, access notes and free-text message are not sent to the platform.
Not sent to the platform
Your experience answer, access requirements and anything in the last box.
Your email
Anything the CTF needs you to know in advance, and pairing you up if you asked for it. There is no separate CTF mailing list to come off.

The form itself sets no cookie or tracker. Site analytics are separate and only run if you accepted them. For questions about your registration, write to us.

No cookie from the form

Changed your mind, or your line-up

Write to the address below and we will edit the entry. No need to submit the form twice. Withdrawing is a sentence, and nobody chases it.

[email protected]

04 Fair play

Five rules that were true before the challenges existed.

Not the full ruleset, which goes out with the programme. These are the part that does not depend on what gets written.

  • Attack the challenges, nothing else

    The scoreboard, the platform, the conference wifi, the venue's systems and the laptop next to you are not part of the game. If a challenge seems to let you reach outside it, that is a bug. Tell us and you will not be penalised for finding it.

  • Flags stay inside your team

    Working it out together is the whole activity. Handing a flag to another team is not, and both teams lose the points.

  • Qualifying solves are checked

    Before the qualifying list is fixed, solves are verified by write-up submission and plagiarism checks. A write-up does not have to be elegant, it has to be yours: say how you got there.

  • Tell us if you break something real

    Say so at the CTF desk, or by email while the online round is running. Nobody is thrown out for a mistake reported honestly.

  • The code of conduct applies here too

    A competition does not suspend it. It covers the CTF room exactly as it covers a talk track, and the reporting route is the same one. How reporting works.

The full ruleset

Not settled yet, and published with the programme and emailed to everyone registered:

  • Categories
  • Scoring
  • Hints, and their cost
  • Tie-breaks
  • Where the cut line falls

Register to get it by email

Writing challenges, not solving them

Anyone who has written a challenge for this edition cannot score on it, and the team keeps that list.

05 Questions

The ones we are actually asked.

Do I need a team to enter?

No. Register on your own and you are a team of one on the scoreboard, which is a normal way to play a conference CTF. If you would rather not, tick the pairing box on the form and we will try to introduce you to other players before the online round, and if that has not worked out, the CTF desk will do it on the spot at the final.

Does everyone on the team need a ticket?

Not for the online round. That one is free and needs no ticket at all, from anybody. For the final, yes: it is played at the conference, so everyone at the table needs to be able to get in. There are two ways to do that, a full conference pass or the competitor pass at ₹799, and they are per person either way.

A ticket reference is optional when registering for the free round. Before the final, every player needs their own pass; one person's reference does not cover the whole team.

Can I come only for the CTF, without a conference ticket?

Yes, if you qualified. The Competitor pass is ₹799 and it covers exactly this much: day one, the CTF final only. It is not a cheap way into the conference. It does not cover day two, the talks or the villages floor, and who may buy it is narrow: players who qualified in the online round.

If you get here on the competitor pass and decide you want the second day after all, you are not buying a second ticket. Pay the difference between ₹799 and the current price of the Student, Individual or Corporate pass you choose. So qualifying during a later, dearer pricing stage does not cost you more than buying the full pass would have on the day you upgrade. The upgrade does not close when sales do. Ask by email, or find any of the team on site before or after the final, and they can sort it there. The address is [email protected].

How long does the online round run?

36 hours. The date is 17–18 February 2027. It is a window rather than a sitting: you are not expected to be awake for all of it, and the hour it opens goes out with the programme and by email to everyone registered.

I have never played a CTF. Is it worth entering?

It is the reason the entry-level challenges exist. They are real challenges pitched low, not participation trophies, and give someone who has never played a place to start. Say on the form that it is your first one and we will point you toward them.

Can I play remotely?

The first round is online, so for that one, yes: register a team and play from wherever you are, on 17–18 February 2027. The final is not remote. It is on site at a Dehradun venue, to be announced, on day one, on your own laptop, and only the top qualifiers from the online round play it. Bring a charger and assume the wifi is busy.

Do we have to send in a write-up?

Qualifying solves are verified by write-up submission and plagiarism checks, so plan on being able to explain how you got a flag. Whether every team submits one or only the ones a reviewer looks at is being settled, and the ruleset that goes out with the programme will say which. Either way it is not a writing competition: rough notes that show the route are the point.

What if we do not qualify?

Everyone who played the online round is emailed the result either way, rather than left to work it out from a scoreboard. The round itself cost you nothing, so there is no refund to chase. If you have a conference pass it is not a CTF ticket: it still admits you to both days, and the villages floor on day two is the other half of the hands-on programme. See the villages.

Will I have to choose between the CTF and the talks?

No, and that is why the programme is arranged the way it is. The CTF final is on day one, alongside the workshops. The talks and the villages floor are on day two. The one clash the shape does create is between the final and a workshop on day one, and the hours for both go out with the programme, so you will be able to plan around something specific rather than guess.

What are the prizes?

To be confirmed
They depend on sponsorship, and we will not announce a prize we are not certain we can hand over. If your company would like to back it, the sponsor page is the place to start.

What tools am I allowed to use?

Assume the ordinary answer: your own machine, your own tooling, the internet. The one thing that is not allowed is taking a flag from outside your team. The ruleset published with the programme is the authoritative version, and if it restricts anything unusual it will say so plainly rather than in a footnote.

Can I write a challenge for it?

Possibly, the set is tuned by the team, and the team is volunteers. Email [email protected] with what you have in mind. Writing one means you cannot score on it, which is worth knowing before you offer.

Play it

Start with the free qualifier.

Register solo or with a team of up to four. We will email the start time and full rules before the online round. Top qualifiers reach the final on day one.