Challenge 1 launches at 3pm today, and we really hope you enjoy it. Jodie has set it up to be reasonably straightforward, even for beginners, but you might want to familiarise yourself with the cipher tools page here at BOSS if you are a beginner. Jodie has drafted some hints for you, and you may find that useful!
As usual we ask you not to post solutions or hints on the forum, but if you want to discuss the story there, that would be fine. Just make sure not to give your opponents a clue by revealing cribs!
There are loads of other helpful resources here on the site, including a completely free beginners’ guide to codebreaking, the official BOSS cryptanalyst handbook, but that is just to get you started. Madness’s guide goes a lot further and that is free too! Head over to the library to see a whole host of free downloads alongside a list of our favourite books with a codebreaking or spy theme.
If you are running a maths club based on the challenge then you might find the slide decks on the BOSS Training Division page useful. Again it is all free, and if there is anything missing that you would like us to consider adding then you should let us know.
If you have questions about any of this then do head over to the forum to ask them. As we said before, we have hoards of experts waiting to help (most of them other competitors) and it is a friendly place to hang out

P.S. a reminder: you don’t have to submit solutions to A and B in order to take part in the competition, you will get individual certificates and leader board entries for each part you enter, but your position on the overall leaderboards will depend on all your submissions, so the more you try the higher you are likely to appear.
That last paragraph was a little misleading, as it is not true that the overall leaderboard depends on all your submissions. In fact that is wrong in two ways: firstly, your score for a given challenge (part A or part B) is based on your best attempt at it. You can try multiple times and we only use your best score; secondly, the first three challenges, 1A, 1B, 2A, 2B, 3A, 3B are for practice only, we will publish certificates and leaderboards for them, but they don’t count towards the overall standings, which start with Challenge 4.