It's taken over 20 years, but there's finally a Pokémon live-action movie. Detective Pikachu may be based on the 2016 game spinoff, rather than the main RPG series, but with its photo-realistic creatures and focus on their relationship with humans (albeit due to the rules of Ryme City, not trainers), it's very much delivering on that built-up anticipation.

The man tasked with the unenviable job of bringing the world to life was Rob Letterman, initially a director at Dreamworks and later bringing the Goosebumps franchise back in 2015. Screen Rant recently caught up with the director to discuss the film's development - and that of fellow 2019 release, Sonic the Hedgehog.

You must be over the moon with the reaction to the movie.

You know, I don’t look at the reactions. I just hide under my couch, so I don’t know what’s going on in the real world. I’ve been so nervous.

Fair enough. Well, I think the movie’s fantastic. I had a great time. It was so much zanier than I expected – just the depth of weirdness to the world, yet containing a very emotional and human story. I wanted to talk about the process of deciding how you were going to focus on different Pokémon. Jigglypuff feels logical with the singing, but Ludicolo as a bartender or Greninja as these weird, experimented on things… How did you decide which Pokémon were going to have which roles?

The movie’s based on this Detective Pikachu video game that was in development at the time, in parallel with the movie. In that game, certain Pokémon were baked in, like Ludicolo. So there was that, and then there was a nod to the first generation because we wanted Pokémon fans in their 20s and 30s to connect with the movie with their favorite Pokémon that they may have grown up with. Like the fan favorite list. We worked very closely with the Pokémon team throughout the whole process because we wanted to be authentic and be right for the fans. We combed through the list to pull out the ones we thought we could do an amazing job of with photoreal CGI versions. So it was all of the above.

You talked in another interview about how Sawk wasn’t able to make it into the final film. Was there a Pokémon you really wanted to include but couldn’t as a result of budget, narrative or design issues?

Well, there’s over 800 Pokémon and I ended up with about 50 or so in the movie. So, there’s about 750 we couldn’t afford to do. It would have broken the bank five times over to try to fit them in. Yeah, there’s a lot I would have loved to have gotten in, but we couldn’t because it didn’t fit with the story. We hint at Legendary Pokémon if you look really carefully at the film, and this Detective Pikachu film is connected to the overall universe. It’s just a different region within the whole world of Pokémon. I would have loved to have them in there, but they have their own storylines and their own backstories and they wouldn’t have fit into the Ryme City region. If the movie does well and we get to keep going, then we might get closer to that 800.

You mentioned it’s around 50. Do you have an exact number of how many Pokémon are in this movie?

I don’t want to get this wrong. I want to say 54, but I may not be right about that because I lost count at one point. Do you mind doublechecking? People are going to be out there counting them, and I don’t want to be wrong.

Detective Pikachu Magikarp

I liked how this movie exists in the world of Pokémon but doesn’t overstate references. But one that really stood out was Kanto, in reference to Mewtwo. Does that imply Team Rocket exists in this world, and that they’re fully functioning?

I can’t answer that question without getting into enormous trouble. You know your Pokémon well, but you’re putting me on the spot. The fact that Mewtwo is in means that Mewtwo storyline is accurate and all that stuff exists.

On a similar note, would you be able to comment on whether Ash or Red exists in this world?

We haven’t thought through where we land in the overall timeline of the Pokémon universe, but we’re connected in one big universe. We didn’t work out where in time we are, because this is just the first entrée into exploring the world of Pokémon in live action.

Spoilers, but I want to talk about Ditto. Because that was the biggest surprise in the movie for me, and I absolutely loved it. How did you go about creating that Pokémon in live action and creating that transforming effect with the weird eyes?

Ditto was a great character to use for a misdirect, which we really wanted to do. There is – I don’t know which episode, but one of the anime episodes has a Ditto in human form with the eyes. So it’s part of the Pokémon canon, and we double-checked [that we got it right.] Having it sort of rifle through every Pokémon in the end fight sequence was just a fun idea. It kind of evolved over the course of the movie. We kept connecting Ditto all the way, until we finally had it woven in from the moment Ms. Norman appears onscreen.

Another Pokémon lore question: you mentioned that Ditto was genetically engineered. Was that a reference to the fan theory that Ditto was a failed clone of Mew, or was that just coincidental?

Man, you’re going deep. That’s incredible, you got me there. From this day forward, I’m going to use what you just said.

Detective Pikachu German poster

[The father] himself at the end of the movie is played by Ryan Reynolds, which was a fantastic appearance that was only hinted at in the original game. Was it always the plan to have whoever voiced Pikachu be in the movie in live action?

It wasn’t always the plan. I just love the pitch that the father he’s looking for has been with him the whole time. That’s really what drives the entire story. The father and son story is just really relatable. I’m a dad; I have a son. It’s something Ryan really related to and responded to. It’s the heart of the whole film, and it gives it the human importance.

With that role, it makes casting Pikachu so much harder. You can’t just cast someone who has a good voice for the character, you need someone who can show up at the end and believably be Harry. Did you consider anyone other than Ryan to play that role?

We considered a lot, but the truth is we needed someone who can be hilarious and dramatic. Someone able to balance both those things. But the truth is we kind of cheated. We took a clip from one of his earlier movies, The Change-Up, and animated Pikachu to it as a test. And the second that was done, it was like magic. It was perfect; there was no other choice. Once we had that, then we reached out, chased him down, and practically begged him to do the movie. It was his daughter seeing that animation test which talked him into doing the movie, so she gets all the commission.

You’re not the only video game movie coming out this year. Sonic The Hedgehog’s trailer dropped recently, and they announced that they would be changing the design because fans weren’t too happy with it. What are your thoughts on that, and do you have any advice for the team working on that movie?

That’s a tricky question. It’s not my place to do that, but all I can say is that [for us] it was all about making sure we hit it right for the hardcore fans. We worked so closely with the Pokemon company, and the original designer, Ken Sugimori, who drew Pikachu originally. We worked directly with him and his time with all the concept art. We spent a whole year in advance designing all the characters and getting them ready before we started shooting. In our case, we wouldn’t have been able to [do that]. If Pikachu had been adjusted by one inch, Justice Smith’s whole performance would have been out the window. We had to have it all baked in upfront.

Next: Pokémon's Movie Future After Detective Pikachu Explained