In short, the model of play of LiveHack is similar in many ways to the play of http://en.wikipedia.org/wiki/Roguelike games, with some important exceptions. Note that the name of the game is based on a popular Roguelike game called NetHack, the “Live” meaning to imply that although like these games, this is played moderated by a living, breathing Game Master (hereafter GM).
The greatest similarity to Rogelike games is that the game is meant to be a somewhat nonsensical dungeon delve, where the player pays most attention to the challenges of survival, acquisition of character power, and progress towards a final win condition. To ease the burden on the GM, this designed to be played in a randomly generated dungeon, making preparation nigh instantaneous. The characters (called Adventurers) live their whole lives, running around this dungeon environment, dealing with environmental issues of food, light, and rest, while also trying to deal with the many monsters that exist there to slay them.
The game does all of this in relatively rigorous fashion, just as a roguelike game does (and in contrast to how some live RPGs work). Optimally, the GM will never have to resort to fiat to answer a question of success or failure, or even quantification of results. LiveHack should almost not require a GM, just as a CRPG does not. Almost.
Note that this makes this game completely unsuitable for those who prefer the sort of free-form problem solving that some people ascribe to play of early versions of D&D, where resolution of most actions is a matter of convincing the GM that the player's clever plan for their character's success will succeed, and having the GM decide on that success or failure without reference to any standardized mechanics. In fact, if anything, LiveHack is a reaction to that sort of play.
The rigor in question with which the game approaches things might seem to make it relatively dry and uncreative, limiting player options to a set pre-set options that prevent a player from doing the “anything” that RPGs seem to promise as a response. Indeed, in an actual Rogulike game played on a computer, this is the actual fact (although there is some slight amount of emergent play that's possible, even in those games). But unlike Rogelike games, LiveHack does require a GM who has a very specific purpose in play. Yes, because of the nature of the model of play, the GM will be responsible for much of the work done in most RPGs, in terms of delivering descriptions of the world to the characters,and adjudicating results of the mechanics, since there is no computer interface to do this work as there is in a rogeulike game. Imagine, however, that if one were to create such an interface, that this would leave only one real duty for the GM.
No computer model yet extant at the writing of this game can perform the cognitive process of discerning from the infinite number of potential character actions how to resolve them all using a mechanical model. This is the most important role of the GM in LiveHack. The SRD does attempt to be somewhat completist in trying to define the resolutions of as many actions as seem likely to come up in the course of adventuring through a dungeon. It cannot, however, come anywhere near to being actually comprehensive. Though it might cover more than 90% of actions in actual play, there will come many moments where the players decide to have their adventurer attempt something that's does not have a specific method of resolution defined in the book.
LiveHack has a simple method of resolution, and set of abilities, which should hopefully make it easy for a GM to discern what abilities make sense to use in a roll to resolve a particular action. And, yes, the GM does have a responsibility to determine when an action is either so probable, or so improbable as to not require a roll, just as in all RPGs. But where the GM is not absolutely sure, he can simply assign a very high or very low DR to a roll, and let fate decide. There is NO POINT where the GM must decide the success or failure of an action by fiat. And indeed, the mandate in LiveHack is to maintain the appearance of a rigorous simulation of events, in order for the player to feel the illusion that their progress through the dungeon is a matter of their characters encountering a sort of complex “physics model.”
LiveHack is very much not a “Balanced” game. Some characters will likely be more effective than others. That said, the resolution model seeks to make as many options as possible viable. And to encourage players to make diverse characters, they are also encouraged to work outside of the boundaries of the standard actions suggested in the SRD, to reduce that notional 90% down as low as they can. To create entirely new strategies outside of hacking monsters to death, and taking their stuff. Note that the monsters, for their part, will be trying actively to reduce the game to this level, which is one that they will likely eventually win. Since this is the case, it is prudent that the adventurers be ready for dealing with monsters and traps etc. This is what the game is about to some extent. But it is also about how to avoid getting too mired in that method of proceeding in order to up the percentages.
Or, you know, kill em all if that's what you're feeling like.
Given that we want to encourage creativity, do not punish the players for it ever. If the players come up with some method of proceeding that makes things seem “too easy” then they're playing correctly, and should be commensurately rewarded by the system. If the players find that such a strategy becomes degenerate, making the game too simple, then it's up to them to request that the GM change the game model in some way to make it more difficult. The GM has no responsibility to try to increase or decrease the challenge in LiveHack. The GM's role is simply to add content where needed, and to act as a complex command parser.
If this sounds interesting proceed on to Adventurer Construction.