As our game's core mechanic is chaining cards with different elements and abilities together specific to each enemy, it quickly became apparent that my most frequently-used effect, card placement, would need to account for variation in chain intensity and element types. The Wwise event plays the a refined version of those two layers together in order to form the card placement sound. 

I prefer to use less events with more variability in order to simplify the in-engine implementation process (and protect myself from needing to make lots of updates down the line), so I decided to handle this using Wwise's state and RTPC game sync features in order to fine-tune this single event with maximum variability.

For the elemental layer, I created a switch container based on the "card_element" state group. The correpsonding state from that group  determines the audio file to be played for that layer (card_fx_air, card_fx_earth, ...).

In the related script, I used the Wwise API to update this state:

The impact layer's purpose is to convey growing intensity as players chain cards together and come closer to completing their attack.

Since different enemies require different numbers of cards to complete the chain, this needed to be flexible. So, I decided to create a Real-Time Parameter Control, since this is a continous parameter which uses a float variable type as its input variable. This would allow us to set the precise intensity by updating a global variable which calculates number of cards played vs. the total number possible.

Since the song was broken into segments including an 8-bar intro (before the loopable song area with all instruments), I created a music playlist container which held two music segments, one for the intro and one for the main song. I set these to "sequence continuous" (so they play in order) and set the intro loop count to 1 and the loop count of the main section to infinite. Since the initial imports didn't work as expected, I had to tweak in the music segment editor a bit to get the transition and loop to play through seamlessly.

Wanting the music to have a nice fade in, I set the music playlist container to add a high-pass EQ filter when the game state is set to "menu".

For more about the music itself, see the corresponding section below.

Beyond simple volume adjustments after using soundcaster and playtesting, I wanted to make sure the dynamics were considered. 

Since the card placement sounds had lots of heavy, impactful content, this created a clash with the music, specifically in the mid-low frequency area. In order to mitigate this muddying of the mix, I decided to feed these interactive card sounds into their own bus and to use these impulses as a sidechain which compresses the volume of the music when they play.

In the SFX bus, I've added the Wwise Meter effect, which takes the incoming signal levels and feeds these into the "sfx_vol" RTPC.

Then, I set up the RTPCs for the music bus, so that its volume decreases when the "sfx_vol" parameter exceeds a threshold of -20dBFS. Using Soundcaster, I tested the effect, trying different attack and release settings until the effect solved the masking issue without being immediately noticeable to the listener.