I was using a random Matrix generator here for a 3rd Edition Matrix run and it came up with Reactive Trace IC. I wasn't sure if this was possible since I thought Trace IC had to attack the decker in combat as the first step, which would seem to be difficult not to notice.

Or am I thinking incorrectly about Reactive vs Proactive IC? Could you have Reactive Trace IC which becomes active at a certain security level but does nothing unless you actually do the magic thing to trigger it in a similar manner to Tar Baby IC?

Trace IC is kinda tricky to classify. it's between white and grey, and it acts both proactively (during the inital lock-on) and reactively (during the location cycle). i'd have classified it as proactive in the tables, but it doesn't really matter.

Been awhile since I've done 3rd Ed... my understanding for Reactive Trace IC was that it only 'woke up' when a particular event got triggered.
Meaning it doesn't roam the node like most IC or sit in one spot where you can see it, it's dormant... but if you trigger a certain event or keyword, then it becomes active.
Much like an IRC bot that'll sit in channel and do nothing till someone types a swear word, the bot then script kicks in..

Thanks for the replies!

So, my question now is this: If Reactive IC is possibly tied to a specific event like accessing a certain file, then how does that work with the Security Sheaf? Does it activate even if the decker has no Security Tally? Or does the decker's Security Tally need to be at a certain level AND they have to access a certain file (for example) to trigger it?

i don't see anything in Matrix about Trace IC that only reacts to certain stimuli (a file being opened, for instance). the only type of IC that activates in response to a specific stimulus is Data Bomb and its variant, Pavlov.

if you wanted Trace IC to activate in response to a specific stimulus, you could do it. simply use a Data Bomb with the trap (Trace) option. when the Data Bomb goes off, it crashes itself, activating the Trace.

and yes, Data Bombs (and Pavlovs) activate when a file is opened, regardless of a decker's security tally.

Ah, so you're saying that you can't choose whether IC is Proactive or Reactive. The IC just does what its description says it does when its triggered by the Security Tally and Proactive/Reactive are just classifying the IC based on those descriptions. Is that correct?

correct. when i think about it, i really don't see why they bothered with the proactive/reactive classification. there's no specific game effects that relate to that; yes, some IC makes attack rolls and some IC doesn't, but trying to differentiate with a whole classification just confuses people.