500 words, the annual short story competition for children aged five to 13, has launched on Chris Evans's BBC Radio 2 Breakfast Show.
The winners will be revealed on 8 June at the Hampton Court Palace Festival.
Their prize will include a ride around the palace in Chitty Chitty Bang Bang, plus Tea on the Thames on the Queen's rowbarge, Gloriana.
Calling the competition "Chitty Bang-tastic", Evans urged children to "fire up their creative engines".
This is the eighth year of the Breakfast Show's initiative to get children writing, which received 131,798 entries in 2017. The closing date is 19:00 GMT on 22 February.
The rules simply ask that entries are no more than 500 words long.
The Duchess of Cornwall is judging, along with authors Malorie Blackman, Frank Cottrell-Boyce, Charlie Higson and Francesca Simon.
The 500 Words initiative is also launching some new features, including:
- A weekly podcast called 500 Words Bedtime Stories
- An entry form allowing teachers to submit a whole class worth's of stories
- A Live Lesson on 15 January at 14:00 GMT, hosted by Barney Harwood and Helen Skelton
- Inclusion of wild card entries that show exemplary originality
- Access to an Oxford University Press (OUP) learning pack and factoids for podcasts
Some of the authors and judges have offered writing tips, with Cottrell-Boyce suggesting that children simply "have fun with it".
"Don't worry about the spelling or 'wow' words," he said. "Just make us laugh, make us cry, make us scared."
This was echoed by Malorie Blackman, who added: "If you enjoy writing your story, we'll enjoy reading it."
Simon said "thinking of an idea that you care about... and then finding your voice" was a "fantastic accomplishment".
500 Words judge, Charlie Higson, said: "I'm really looking forward to reading this year's entries and seeing what kids have been thinking about and writing about.
"As someone who writes for younger people it's really interesting seeing what stories kids like to tell. The depressing thing is that they're mostly better than mine."
The judging panel will choose gold, silver and bronze winners in each of the two age categories - five to nine, and 10 to 13.
Livia Turner, last year's gold winner in the 10 to 13 age category, said it had been "an amazing year", adding: "There's even talk of my story becoming an animation!"
The gold winner of the younger category, Lauren Cook, said: "I've been on the cover of the school yearbook with a picture of me surrounded by all the books I won for the school library. That bit makes me feel really proud."
Winning entries will be announced and read out by celebrity guests, known as "superstar narrators".
Previous readers of the winning stories include Sir Kenneth Branagh, Benedict Cumberbatch, Tom Hiddleston, David Walliams and Dame Julie Walters.