QUOTE (phlapjack77 @ Dec 23 2012, 08:28 PM)

Is there a rule on this you can point me at? I've never seen this before.
SR4A, page 67,
Initiative Passes (basic rule).
SR4A, page 74,
Spending Edge, fifth bullet (Edge rule).
SR4A, page 145,
Initiative Passes (basic rule expanded).
SR4A, page 196,
Improved Reflexes, third sentence ("cannot be combined with technological or other means").
SR4A, page 208,
Increase Reflexes, third sentence ("a single Increase Reflexes spell at a time").
SR4A, page 226,
Cold Sim, second paragraph, second sentence ("receive an extra Initiative Pass").
SR4A, page 226,
Hot Sim, second paragraph, second sentence ("receive two extra Initiative Passes").
SR4A, page 254,
Effect (general rule).
SR4A, page 257,
Cram (nothing saying it can't combine).
SR4A, page 257, Jazz (nothing saying it can't combine).
SR4A, page 258, Kamikaze (nothing saying it can't combine).
SR4A, page 342,
Wired Reflexes, fourth sentence ("cannot be combined with any other form of Initiative enhancement").
SR4A, page 347,
Synaptic Booster, third sentence ("cannot be combined with any other form of Initiative enhancements").
Augmentation, page 41,
Move-By-Wire System, third paragraph ("cannot be combined with any other form of Initiative enhancement").
That's all I feel like finding for you at the moment, but here's a rundown:
The rule is specific for each item that affects your Initiative/Passes. Wired Reflexes, Move-By-Wire, Synaptic Boosters, Improved Reflexes, and
Increase Reflexes specifically state that they do not stack with anything else, whereas the effects of drugs, VR (cold or hot), and Edge says nothing about it. By inference, since the other forms specifically disallow stacking that means the general rule is to allow stacking. Even if you have Kamikaze, Cram, Jazz, and spend Edge you are still limited to your 4 IP. Only the Simsense Accelerator (
Unwired, page 198) specifically allows this stacking to go above 4 IP, and only while in Hot Sim.