Yes, I do know that its clearly stated in the book that when your dice pool reaches 0 you automatically fail at whatever you're trying to do and that you can expend karma to do a "long shot" or something of the like, but still I think that the system needs to be more "granular" when the dice pool is near 0. 1 dice is equal a 33% chance of doing something, 0 is... 0% chance. So, i'd like to try a house-rule and would like to know what do you guys think about it.

While your dice poll is 1 or more, the rules are the same, but, when it is lowered, instead of going to zero, its begin to "increase", so, 0 dice are actually 2 dice, but, instead of needing at least 1 sucess, you need all your dice to turn up 5 or 6, giving you a 33/2 = 16% of chance of actually doing something. That manner you don't even need to stop the penalties at "zero", if your poll is reduced to -1, you need to throw 3 dice and to suceed at all the 3, at -2 you roll 4 dice at the same situation and so on.

It is much trouble for what it is worth? It is unbalanced or broken? I think that the major impact will be on NPCs rolls, because they are the ones that have the smaller dice poll.

Do you just dislike the Long Shot Rules? I mean, every player has an edge of one at least. If they don't use it for those times that they really need to take a shot rather than manuever to a better position then what the heck is luck good for. I think this is just a sill complication considering there is already a mechanic in place, but if it doesn't fit you're game, do what you want. NPCs have group edge for a reason...or they move to a better position. If they are continually reduced to 0 DP and the PCs are steamrolling them you need to upgrade your NPCs. Almost all DPs of the same type of roll (combat, spellcasting, etc) will suffer from the same deductions. Yes, PCs tend to be optimised in their particular niche...why aren't your NPCs? I don't mean broken, just on par with the PCs. Sure you should have some mooks who sling 6-8 DPs, but if your group is slinging 15-20 DPs why not swing back with a couple of the same? Makes it challenging, natch.

I think it's too complicated, personally. I had to read it twice to understand the progression you were describing. I agree with the previous poster, I'd beef up NPCs before I worked in a house rule like this. Don't forget about the Home Ground merit. It's not too useful for PCs, since most Shadowrunners end up doing their most lethal work in places with which they're not familiar, but for a guard to have Home Ground within the building they're guarding isn't too bad. That's an immediate +2 to your NPCs when you give them the merit. Maybe the rent-a-cop guard rotation doesn't have it, but it's useful to give to lieutenants and other more powerful NPCs.

I understand the temptation to do this. The abrupt change from 1/3 to 0 does seem odd. But there are all sorts of odd corners in the odds in shadowrun. There always have been (although the corner cases move around a bit.) But it is not worth fixing the oddities. (For example, the change of a critical glitch on 1 die is about 16%, while the chance of a critical glitch on two dice is more than 19%. So be it.)

But the reason for posting this is just to make sure other folks are not confused by your odds calculation. The chance of getting two successes on two dice is 1/9, or about 11%, not 1/6.

Joel

Well, I'd rather take the simple rules. 2 dice - 1 die makes 1 die and 1 die - 1 die makes 0 dice. I do not need any formula that defines if I can still act beyond that - we have roleplaying for things like that. Also you don't get down to 0 dice without a reason

Well, thanks for the replies and sorry for the broken english: it is not my primary language.
The two main reason for me to design such a house rule is:
1 - I still think that we need something more possible than "luck alone" (long shot) and 16% chance.
2 - Once you reach 0 dice, there is no reason for you to bring all the penalties (as it will remain at 0) and then use your karma. Maybe I overlooked some parts of the rule but, if you're trying to hit some punk at dificulties so dire that your dice poll is reduced to 0, there is no reason to not try to hit him in the head (maybe -4 to dice for +4 damage) tresspacing his armor (penalty equal to his ballistic armor) and at a full uncompensated burst with a heavy weapon: You're still using your Edge and your dice poll will be [Edge] Dice.

The GM can always say no.

In SR4 getting your DP modded down to 0 is usually a good indication you're doing something terribly wrong or your opponent is doing something terribly right...
Still giving people a chance to succeed with a DP of 0 or less doesn't mesh well with the rules as they stand now...

By RAW, this is true, as soon as you make a longshot, you can just start pilling up the mods...
Our group has the unwritten rule that mandatory modifiers apply first (visibility and such) and voluntary modifiers can only be applied if you are still over 0, but if you have a DP of 1 after all mandatory mods, you can take a -4 for +4 damage.

I'd say you're better off converting some die penalties to threshold penalties instead for more granularity.

Instead of having something drop from 2 dice to 1 die, have it raise the threshold from 1 to 2.

That would create the same problem if you'd go from 2 dice to 0, the threshold would be 3 with 2 dice, which is also a no go...

You could borrow a page from the old Star Wars d6 rules. Have one die in your pool always be an exploding die. Just one.
I'm not recommending screwing with the long shot mechanics, but since you're already considering it, that might be a good way of having the increasing threshold and keeping a shred of possibility.

Like I said, for more granularity, you'd need to change penalties to become threshold modifiers instead. If you wanted more than that, you'd have to change some of the penalties that drop them to 2 to threshold modifiers. Really, more work than I care to bother with, it was just a suggestion for the OP.