My house rules for Shadowrun Addiction, to take into effect multiple uses, and frequency of use. Now, before I go into this, the reason was because there were several parts of the current Addiction rules that didn't make sense, or seemed way too complicated. Taking into account average die rolls, someone who drinks 1 Soykaf per week will eventually hit Burnout and fall into a coma. Yes, as Michael (who did the math) pointed out.
If you drink Soykaf ALL the time, you'd be rolling once every 10 weeks. Let's assume Soykaf is Psysiological, so Body+Willpower to resist, that's 6 dice for normal people. 2/3 chance to succeed, so once every 30 weeks you'd fail. So you'd have to be dosing on Soykaf for 2.5 years average in a row without ever taking a break to start hitting Burnout. If you're a runner with decent stats, it's 90%, so 100 weeks per failed test. That's 8 years average of constant Soykaf drinking before Burnout.
It would take years, but the Soykaf drinker will eventually hit 0 in some stats, and that just doesn't sound reasonable to me.
Another reason I wanted to come up with something slightly different, is because in the current rules, a person who takes kamikaze once per hour is just as likely to get addicted as someone who takes it once per week. Again, to me, this just didn't seem right. It didn't take into account binge users, and I wanted to do something to make it more risky for the frequent users, over the casual users.
So, here goes.
1. When you roll your addiction test, you aren't trying to beat a threshold, but an opposed test (opposed test is an amount of dice = Threshold). This makes it a little easier to resist the first use, I know, but the presumption is that users aren't going to use just once, and it gets more difficult, as seen below.
1a. To simplify this process, the GM can allow for "Bought" hits on both sides, unless both sides have enough dice to buy the same number of Hits, then roll. (Ultimately, addiction might not fit into everyone's game. And partly, this is for those GMs that want to have something for those Players who took the addiction Negative Quality, but don't want to go overboard, and soon have every PC in the game addicted to something).
2. Addiction Rating can be used to factor in the frequency in which the addiction test changes. For Ratings 1-3, every additional use in the same day adds 1 die to the opposed roll. For ratings 4-6, every additional use in the same week adds +1 die to the opposed roll. And ratings 7-9, every additional use in a two week period adds +1 die to the opposed roll.
2a. Another way to calculate this, if you want a little more bookkeeping, is to use the Addiction Rating as the interval itself. Something with an AR 1 would count additional uses per day, something with an AR 2 would count every 2 days, up to the big stuff counting for multiple uses within a 9 day period. I, personally, would stick with the day/week/2 week, because it makes it easier to keep track of, in combination with 3 below.
3. Every week you skip usage can reduce the opposed roll by 1 die. Using the normal 2 week period for a roll, drugs with 1 die, that are skipped for the second week, are at 0 dice, so you are safe. Or, if you want to require rolls at different intervals, you can. Whatever the GM wants here.
4. Under this system, you can force a roll when it is dramatically appropriate, assuming bought hits don't pass the test (see 1a). Or, for the case of frequent users, you can require a roll, even if Bought Hits would normally pass the test. Ultimately, this system allows for binge users to have a tougher time resisting addiction, but it doesn't severely hurt very casual users, specially causal users of things like soycaf.
The rolls are the same, Logic + Willpower for psychological, and Body + Willpower for physiological.
If you go with the rules as they are, someone with a soycaf addiction will eventually reach the burnout stage, and then start taking permanent stat reductions until they slip into a coma. And, someone taking 10 doses of Kamikaze a day had no more trouble with addiction that someone who took 1 dose per week, and I wanted to make it harder for the binge users.
So, here's an example of how this works.
Character has a Body 3, Willpower 3, and Logic 2. Let's say She takes some Cram, because she wants a combat Edge. If the GM wants an immediate roll, she would roll 5 dice (psychological) vs Cram's 3 dice. Using Bought Hits, she has 1 Hit, Cram has 0, so she is not addicted. Since Cram's AR is 4, as long as she doesn't take another dose within the same week, she should never really have to worry about addiction. But, if she takes another dose within a week, The opposed dice test would now roll 4 dice, enough to buy a Hit, so the GM should require an actual roll next time, Her 5 vs Cram's 4, instead of allowing the buying of Hits.
Now, if you want to keep a Threshold, instead of opposed Roll, you can. This system allows for that, and still makes it difficult for multiple uses in an interval, just add to the threshold, instead of the opposed die roll.
Anyway. If you want to use it, by all means. If you have ideas to keep it effective, but simplify it a little more, I would like to hear it.
