At the GDC in San Francisco this past week, I had the opportunity to spend quite a bit of time with John Abercrombie of 2K Boston and the AI lead on Bioshock. It had been a heck of a week for the entire Bioshock team since their title had not only won many awards and accolades prior to GDC but also had a great showing at the Game Developers Choice Awards (they lost the Game of the Year award to Portal… in which there is no shame). Despite having been pestered relentlessly all week to speak about his AI work with the title (he probably talked about it as much as if he had given a lecture on in), he was gracious enough to sit down with me on Sunday morning and chat with me about it on tape.
I want to mention a few things here first…
- I’m not a professional interviewer. I’m an AI guy just wanting to pick someone’s brain.
- We were sitting in a hotel lobby so there is a bit of background noise.
- We didn’t have a white board or anything else so we didn’t really get “down to the metal” on any of these subjects – no code, no diagrams, etc.
- We could have gone on forever that day, but Laurie and I had to catch a shuttle to the airport.
- The one requirement his boss put on this interview was that I mention (loudly) that 2K Boston is hiring AI Programmers!
In case the above applet doesn’t load or it is playing at the wrong speed, you can download the actual .mp3 file.
Here’s some questions (paraphrased somewhat) that I asked and topics we discussed throughout the interview (listen to the audio for his answers and descriptions):
(0:41) How did you manage some of the issues with the potentially different factions? That is, splicers fighting splicers, the Big Daddies fighting the splicers, etc.
(5:35) Are the Splicers trying to get at the Little Sisters by default and thereby annoying the Big Daddies or is that just accidental?
(8:00) We discuss the game design mechanic of being able to choose the time and place of your “boss battle” and then actually wander around and watch the boss (Big Daddy) interact – even in combat with the Splicers.
(11:30) John talks about how the Splicers react to being cornered by the Daddies.
(12:50) What other things were you doing with the perception systems?
(19:35) We discuss how the enemies (e.g. the grenadiers) will adapt their tactics to you… both as an intelligent reaction but also to adapt the gameplay to specific difficulties in dealing with the interface and some plasmids.
(21:28) John talks about a small horror story with regard to ballistic physics and the “rifleman’s rule“.
(25:19) John talks about how the Daddies will use things like proximity grenades to box you in – but that how the Splicers don’t even notice them.
(27:23) John talks about how the design decision surrounding whether to have the Splicers and Daddies avoid fire.
(28:13) I ask about the different tactics that the enemies use and how they select between them. Also, how they had to do workarounds to keep players from exploiting things like the pathfinding grid. He goes into detail about how this was beginning to get computationally expensive.
(34:26) What’s your biggest horror story from the whole process? (John responds with an amusing anecdote about some early behavior tests.)
(37:24) What’s the coolest thing that you pulled off?
(38:53) On Soren Johnson’s scale from “good AI” to “fun AI”, where do you think Bioshock fits?
(40:50) Do Splicers continue to spawn on a level until you leave it?
(43:00) We briefly digress into talking about the audio (which won awards).
(44:28) Not counting development time, how many times did you play through the game?
(45:24) The mandatory “2K is hiring” plug!
(49:04) John tells the story about his wonderful moment after the game is shipped. (As game developers, don’t we all want to hear this?)
(Total length 50:56)
If you want to hear more of John’s comments on various subjects, you can listen to the GDC AI Roundtable audio files and read my notes here. He spoke up once or twice in there.
Again, I want to thank John for taking the time with me for the interview… and being a pretty good companion throughout the week of GDC. I enjoyed it quite a bit.