To begin with, The Walking Dead stuck pretty close to Robert Kirkman's comic book series. However, the moment Shane made it out of that first camp alive, it was clear AMC's adaptation was doing its own thing with the source material.
Over the years, that proved to be both a good and bad thing, though many iconic moments were left on the page to the detriment of the long-running TV show. Others, meanwhile, alienated viewers (Glenn's death, for example). In the show, Rick's hand was never cut off by The Governor and, at the time of his apparent demise in season 9, the survivor still had both limbs.
Well, that all changes in The Walking Dead: The Ones Who Live as Rick hacks off his hand - cauterizing the wound in the flames of a dead zombie - in a bid to escape the sinister CRM. That attempt fails, but he later acquires a formidable prosthetic to help him battle the undead.
Talking to Entertainment Weekly (via FearHQ.com), actor Andrew Lincoln elaborated on why this is happening now (had The Walking Dead followed the comics, it would have been way back in season 3).
"We had to explain why Rick had never returned," he says. "This is a guy that would do anything to return, so what is the most extraordinary act or effort that he would put himself through in order to try and get back to his beloved?"
"I just bullied everybody into submission," Lincoln adds, admitting he faced some pushback. "And there were quite a lot of conversations, particularly with AMC, with people going, 'Now Andy, we love the idea, but are you really sure about this?' But I just thought: This is the time to do what the comic book did and honor that. I've been trying to pitch this for years, and everybody was just shouting me down."
According to showrunner Scott M. Gimple, making this work on TV required "a commitment to figuring it out, whatever problems might come of it...I think it was important as a comic reader to see it, because it helped set the tone of what this world is that these crazy things can happen."
Kirkman has famously said he regrets cutting Rick's hand off because of the logical problems it often caused for him as a writer. In case you missed it, here's the moment Rick decides to sacrifice his left hand...
In another world, built on a war against the dead, Rick Grimes and Michonne attempt to find each other and who they were.