Alexander McCall-Smith, Anne Boleyn's dog and God himself are taking part in this year's Twitter Fiction Festival, which is running over four days until March 16.

Authors, poets, humorists and novices have been selected to write 140-character stories and tweet them out with the hashtag #twitterfiction. Regular Twitter users are encouraged to join in with their own stories.

The entries for the second Twitter festival have included a wider range of storytelling than the first, held in 2012, with photography and videos, crowd-sourced ideas and multiple characters enriching the mix. But fewer big-name authors are involved in this year's event, which is sponsored by the Association of American Publishers, Penguin Random House and Twitter itself, and the festival has skewed noticeably towards the US since 2012.

Scottish novelist Alexander McCall Smith, Australian Graeme Simsion and American Anthony Marra were among those selected to take part by a panel of judges from the publishing industry. The relative lack of celebrity tweeters has opened up room for the tweeting punters (twunters?) to leave their own mark on the Festival.

For those daunted in the face of unbridled creativity, the instant story generator puts together phrases and sentences to make tiny stories for you to tweet out as your own. "Angelica Huston made a wish on a Mac n Cheese and the rest was history" was my first randomly generated story. I would definitely read that book. Publishers, take note.

Elsewhere, the Twitter-fest feels like a slightly messy experiment. Twitter does not seem a conducive platform for reading a story, when the narrative appears in reverse with newest tweet first.

The 140-character limit is a prison made of jelly, as Alexander McCall-Smith demonstrated - publishing one 5,000-character story in 40 tweets. But the character limit does pose its own problems, as word choice is dictated by the space left, not their effectiveness in the story. The stand-out tweets tend not to be part of the established programme, but from the twunters. Some of the most poignant stories unfurl in single tweets, which stand alone as little pockets of observation and emotion.

But after a night of scrolling through the tweets, I returned to my favourite thing: the instant story generator. "In The Fortress of Solitude, a persistent rash will only set you back a few dollars" will be the first line of my memoirs.

Highlights and lowlights so far (all times listed are UK GMT):

No. 1 Ladies' Detective Agency author Alexander McCall-Smith (@McCallSmith), is creating stories in tweet chapters, entitled 'The Intern', 'Love in the Alps', 'The Sociopaths' Ball' and 'How to Sing Grand Opera'. The first of McCall-Smith's efforts, The Sociopath's Ball is an example of his usual harmless humours. But I can't help but feeling he is missing his usual audience on Twitter and that writing over 40 tweets is a cheeky bypass of Twitter's enforced succinctness.
(Began on Wednesday, continues Friday 12am and Sunday 9am)

The best tweet of the bunch:

Ben Winters' (@BenHWinters) twitter tale is about his plans to write about a fictional man called Atlee Connors who holds up a bank, only to be contacted by a real-life Altee Connors who is furious about the story. It's an intriguing blend of believability and tongue-in-cheek awareness of the blurred line of fact and fiction on social media. Judging by the official description of his story, I kind of believe it. I want to read the original story too.

Relive a climb to the top of Mount Everest called #HighAltitude with climber and journalist Adam Popescu (@adampopescu). Popsecu climbed 18,000 feet while investigating the trash problem on the mountain for the BBC and tweets photos and videos. It is very non-fiction for a fiction festival, but very interesting. One to follow. (Started on Wed 7pm, continues Friday 7pm and Sunday 7pm).

@MeghnaPant retells the The Mahabharata, India's longest epic poem at over 100,000 lines, in just 100 tweets. Somehow, Meghna Pant has managed to contain all of the dynamics of power struggle, war, love, lust and greed in her 140 character tidbits. Wonderfully descriptive and paced. (Began Thursday, continues Friday, Saturday and Sunday, 9am).

Historical fiction with bite: British historical author and columnist Elizabeth Fremantle (@lizfremantle) is tweeting the rise and fall of Anne Boleyn – from the point of view of Boleyn's dog. Tudor The Dog is a charming enough project. If Bridget Jones was a dog…. (Began Wednesday, continues Friday, Saturday and Sunday, 10pm)

What to look forward to (all times listed are UK GMT):

God adding to the Bible: the irreverent Twitter favourite @thetweetofgod brings thee The Book of Bieb, the rise and fall of Jesus' younger brother, Justin Bieber. Run by former Daily Show writer David Javerbaum, The Book of Bieb will be told in 10 chapters – or 241 tweets. (Friday 1pm and 4pm) An indication of the wrath to come:

Father-to-be Jason Lasky (@j_lasky_writer) is documenting his daughter's current experiences inside his wife's womb. With 85 tweets and 50-odd followers, I don't know how accustomed Lasky is to Twitter, but the idea has potential to be fun. (Friday – Sun, 5am)

Author of the bestseller The Rosie Project, Graeme Simsion (@graemesimsion) is writing about Don and Gene friends tweeting back and forth between Australia and New York). Don is advising Gene about his marriage after Gene was caught cheating. Twitter users are advised to contribute to the conversation and Simsion will incorporate feedback into the conversation. (Began on Thursday, continues Friday and Saturday, 9am)

US crime author Megan Abbott (@meganeabbott) has invited Twitter users to submit photos or videos of their favourite locations in film noir in advance. She will then create a noir crime tale using all the locations. (Begins Saturday 1am)

Husband and wife team Tom and Chloe Avery (@teamavery) are tweeting a first person murder mystery through narration, photos and links to completely fictional news stories. (Began on Thursday, continues Friday, Saturday and Sunday, 8am)

Tom Mitchell (@tommycm) is leading a choose your own adventure story through London. Gone are the days of cheating by threading your fingers in past pages, this fictional journey will be dictated by the number of favourites versus retweets. "You offer to buy another round and Nicky suggests you choose. RT this tweet to suggest Brooklyn Lager or 'favorite' for a couple of Sambuca shots." Could be good fun. (Begins Friday, 2pm)

A funeral for a prominent journalist builds into a anti-government riot near a shopping mall. Friends Alia and Cala discover via Twitter that they are both trapped inside the mall. Unable to reach each other, the young women pass comfort and information back and forth as family members, activists and media join the Twitter discussion. Written by US political ghostwriter Lara Prescott (@laraprescott), this could be an thought-provoking combination of photos, characters and interactions. (Begins Friday, 12pm)

To see the entire schedule, visit the Twitter Fiction Festival website.