Book one of Tip Top Phonics has five spellings available to it: s, a, t, i, m. Nothing else. No other letter appears anywhere in the story.
People assume that constraint is what makes decodable books dull. It isn't. What makes them dull is the order the work gets done in.
Most get written by taking the words available at that stage and lining sentences up from them. Sam sat. Mim sat. Sam is at a mat. Every word is readable, and a child can do it, but a page of them is a list with full stops on. Nothing is about to happen and there is no reason to turn over.
We work the other way round. Decide what happens, then find out whether the code will carry it, then throw most of it away.
Let the pictures do the heavy lifting
Here is the whole of book one.
Mim. It is Sam. Tam is at a mat. Sit, Tam! Tam sat. Sam sat.
Twenty words. What makes it work is Sarah Corcoran's illustration: a girl on a mat, a squirrel arriving, a mammoth turning up and being asked to sit on a mat plainly too small for him, sitting anyway, and a squirrel ending up on his head.
The text names things. The pictures do the joke. That is the whole trick of a first reader in a good phonics series.
Why the Ice Age
Look at a shelf of decodable series and a lot of them are set in a house. A cat, a mat, a pan, a bed. There are reasons for that, since domestic nouns are short, but the effect is that dozens of series feel like the same book.
The Ice Age solves several problems at once. Short names sit naturally there, so Mim, Tam, Nat and Pip read as people, not as words picked for their letters, which is what they are. Danger is always available without contriving it, because the cold is a threat, hunger is a threat, and there is a large cat with an interest in the cast. None of that needs vocabulary.
It also gives an illustrator far more to work with than a kitchen does. Snow, fur, breath in cold air, and creatures a child already has opinions about.
Silly is allowed
Wordplay is out. You cannot write a pun with s, a, t, i and m.
What survives is physical comedy and reversal. Book seven of Set 1 is a mystery. There is a large white lump in the snow and Mim and Pip work through what it might be. Is it a fox? Hiss. Is it a yak? Huff, puff. A big, big bug? Buzz, buzz. It is Pop, asleep under the snow, and the buzzing was him snoring. The last page is Pop getting up and falling straight over.
Book eight runs the same shape differently. Viv is missing. Not on her bed, not in her den, not up the hill. Mim jogs all the way to the bog and yells for her. Viv has pups.
None of that needs an extra spelling.
The cast arrives as the code allows
Mim, Sam and Tam appear in book one. Pop, Pip and Nat need n, o and p, so they turn up in book two. Viv waits for v in book four.
Then it starts doing something we did not plan.
The sabre-toothed cat is there from book three, chasing Sam into a bog, and he goes eight books without a name, because his name is Thud and th is not taught until Set 2. When he finally gets it, in the th book, it is because he has turned up outside the den at night, thin and injured, and Mim binds his leg. Two books later he leaps off a rock and puts himself between a short-faced bear and a wolf pup.
That pup is Quin. He is born in the last book of Set 1, one of four, and waits another eight books until qu arrives, whereupon he immediately runs off alone and needs rescuing.
We did not set out to build an arc that way. It fell out of the rule that a child should never meet a word they cannot read, and names are words. What it produced is a series where the villain of Set 1 has a name, a limp and a reason by the end of Set 2.
One other constraint helped. Everything happens in the present tense, because was and were are not decodable early. It has made the books more urgent than they would otherwise be.
The hard part
The first book of any series is the hardest thing to write in this business, and nobody has entirely cracked it. With five spellings you have a scene, not a plot. The honest goal is to make the scene worth being in and make the child want the next one.
It gets easier fast. By book three there is a sabre-toothed cat and a chase across a bog.
Older readers
This is where the dullness problem does real damage. A nine-year-old still learning to decode gets handed books designed for infants, because those are the ones at the right code level, and the pictures are of ducklings. Every page tells that child something about themselves.
The answer is not easier books. It is the same restricted code with completely different content, written for the age of the reader, not the level of the reading. A few specialist publishers have been doing this properly for years and they take some finding.
One thing this is not
The answer to a boring decodable book is a better decodable book, not a book with words the child cannot read. Loosen the code to make the writing easier and you hand the difficulty to a five-year-old, who starts guessing.
Constraint is the writer's job, and it should stay there.
Five letters, twenty words, and a mammoth sitting on a mat that is far too small for him. That is the brief, and how children will build their confidence and enjoyment with reading.