Word Ladder

Word Ladders (also known as word golf, laddergrams, or paragrams) are a type of wordplay puzzle supposedly invented by Lewis Carroll in 1877. The puzzle traditionally involves taking two four-letter words and changing one to the other via single-letter changes, ensuring that each change results in a valid English word.

Background
While several different people have published collections of such puzzles, the earliest known instance of someone creating word ladders as we know them today is with Lewis Carroll, who wrote about creating them in his diary, although he claimed they were originally a two-player game rather than a solo challenge. At that point, he called it "word links", but changed the name to "Doublets" when he began publishing them in Vanity Fair in 1879 (under his pseudonym of Charles Lutwidge Dodgson).

After Carroll, other publications began popping up, but still relatively sparsely. A book of "Laddergrams" was published by Surrick and Conant in 1927, and they became an occasional side-puzzle in some newspaper puzzle pages. In modern times, they've even made it into NYT crossword puzzles as a variation on certain clues.

In popular culture, word ladders have shown up in some puzzle video games, as well as Vladimir Nabokov's novel Pale Fire, in which he mentions his own personal scores for certain pairings (3 for HATE to LOVE, 4 for LASS to MALE, and 5 for LIVE to DEAD).

Puzzle Application
Most word ladders solvers will encounter will be made up of four-letter words, primarily due to the high relative volume of 4-letter words for the low amount of variation they can have. SLIM --> SLID --> SAID --> SAND --> SANE --> SINE --> NINE --> NONE However, it's still possible to encounter those of other lengths. As previously mentioned, five-letter word ladders are perfectly possible, and while 3 and 6 letters ones are often considered to be too easy and too difficult respectively, if the circumstances are right they can still make for an engaging puzzle.

Beyond changing the lengths of the words used, there aren't very many common variations on the Word Ladder structure that don't veer off into other distinct categorizations. The closest that is still sometimes called a Word Ladder are what are essentially modified rebuses; puzzles that give instructions on transforming a word into other words through the swapping, addition, or removal of letters. What this means is that while other word ladders have a uniform width, these would have variable width. With how loosely these types of word ladders can play with their transformations, it's almost guaranteed that they will involve clues to answer or directions to follow rather than leaving the solver to find their own path. VEGETABLE --> TABLE --> STABLE --> STAB --> SLAB --> SLOSH --> SLASH --> DASH --> DISH --> RADISH In terms of how a word ladder is presented (outside of the core structure), there are exactly two forms: clued or clueless.

Clueless word ladders are the traditional "Get from A to B in X moves", where there is no limit but the solver's own word knowledge. These also tend not to be used in puzzlehunts unless they're extremely constrained, as without a guarantee of what words go in the middle, the setter can't make a reliable extraction.

Clued word ladders eschew the concept of forging one's own path, and instead take a pre-forged path and break it to pieces. Usually presented as a list of clues, solvers will likely identify it as a word ladder if they find that the clues solve to words that are all the same length, or once they find two clues that solve to very similar words. The goal of these is then just to rearrange the clues' answers to form a valid word ladder, which will usually only have one arrangement.

Variations on clued word ladders most commonly involve missing words, or creating word loops (where both ends of the "ladder" can connect), with either indexes or the aforementioned missing links providing a common extraction.

Clueless Word Ladders
Clueless word ladders can be approached in one of two ways. Solvers can either attempt to list words that are one letter away from the terminals, or look at what letter changes can get those terminals as close to each other as possible. The former can be very time-consuming for a solo solver, but can reap rewards when either many people are working on it or the process is automated. The latter is much more approachable for a single person, as it forces them to either choose to change letters into the final product immediately, or find changes that allow them to get closer if immediate changes are not possible.

Example: HEAD --> TAIL. TEAD, HAAD, and HEID are not words, but HEAL is, so it's a good first step.

Clued Word Ladders
Clued word ladders are more friendly to crossword regulars, but can still be intimidating as their length is usually much longer than clueless word ladders. Once solvers have begun solving the clues, they should try to fit answers in to a possible ladder as soon as possible, and use the gaps to help answer any clues that are stumping them. Assuming that it's not too gimmicky, working the puzzle from both the clue perspective and the ladder perspective at the same time should help get it done in a flash.

Notable Examples

 * Snakes and Ladders (MITMH 2013) - A metapuzzle from the Indiana Jones round.
 * The Broken Bridge (MITMH 2017) - The metapuzzle for the relevant quest round.
 * Clued Connections (MITMH 2019) - A clued word ladder was part of this puzzle,