Domo Arigato, Mr. Roboto
Or, "Lizard shows his age with that title".
Despite my last design rant being all about the Savage, my own internal "what I’m most inspired to work on" clock ticked itself over to robots. My original thought, as the publication of Alpha 1.4, was to leave robots out of the first couple of betas, but I decided, ultimately, I wanted them in from the start. Rather than simply go with a generic humanoid robot as a single "race", I am creating a simple system of "One from column A, one from column B" picks for such things as arms, legs, and so on, each option with various advantages and drawbacks, bolted on (heh) to a set of standard robot properties.
Robots also push a bit harder against the "Only benefits, never drawbacks!" school of design for 4e. Since I’ve already chipped at this paradigm with mutational defects, cold-blooded reptiles, and so on, I figured I might as well keep pushing. Game design tends to be about elastic boundaries and grey areas, not hard and fast borders. While the closest thing to robots in core 4e, the Warforged, basically have few mechanical distinctions due to their construct nature (the can be poisoned, magically put to sleep, healed, and so on), and while I could have gone that route with only minor handwaving and flavor text, ideally something about "synthezoids" or the like, I ultimately decided to stretch the bounds a bit in terms of making robots feel robotic. I don’t want to detail mechanics just yet, as they’re in serious flux (just wrote them this morning, less than an hour ago), but right now, robots are resistant — though not immune — to poison and psychic attacks, and vulnerable to lightning and acid attacks. (There will probably be mitigating feats).
While it might make perfect sense to make them immune to poison, as most NPC robots are, this is simply "too good" to be easily balanced. Too many attacks use the poison keyword, and it’s a big part of Earth Delta because poisons are a common "special effect" to explain a lot of different kinds of powers and abilities. I do not find it too much of a stretch to say that complex, toxic, chemicals poured into extremely delicate electronics are going to have some negative impact, even if it’s not quite as pronounced as it is for organic beings.
Almost as a side thought, I noted that normal "Heal" checks do not work on robots, but that Technology checks, with identical DCs, can have the same effect. And then it hit me that healing itself might be a problem. Switching skills is trivial, especially given how likely it is someone in the party will be trained in Technology, but there’s a whole bunch of healing type powers and items… can they work with robots? Going the full simulation route and requiring some sort of special rules, items, or powers to heal robots is pretty game-breaking; it either forces the party Leader to invest in these powers or put a robot PC at great risk. For purposes of actually making robot PCs playable, all Healing effects had to work on them pretty much as written.
So, they do. However, rather than just state this and move on, as tends to be the official style, I have a pretty long sidebar/rant on how to flavor text, modify, and describe various types of healing done in the game so that, when applied to robots, they make at least some sort of sense, so the game doesn’t stop dead for a moment while everyone tries to work out what just happened in terms that can be visualized in the game world, not just expressed in the game mechanics. One of the greatest parts of the 1e Dungeon Master’s Guide were Gary’s essays on what hit points and saving throws and so on represented, what they modelled, what it meant when a 10th level fighter was hit by a longsword and took only 8 out of his 60-odd hit points. This sort of description is very rare in 4e, and while some may claim this is done to avoid "limiting" or "restricting" players, the lack of real guidelines and discussions on how to turn game mechanics into descriptions, or even why you should, helps contribute to the perception of 4e as a "tactical wargame". I will not insist my essays on this topic are flawless, or that there will still not be "Huh?" moments and seeming contradictions when healing is applied to robots, but I am trying to give DMs and players some sort of platform, however shaky, to stand on.