I was checking out Toy Story 4 gameplay footage from Buffalo Pinball. And for whatever reason, when Kevin had Buzz multiball going and started Gabby multiball, the thought occurred to me, "Does Elwin never allow multiball stacking in his games?"

I immediately answered my own question (yes), realizing the game of his I know least well (Avengers) allows it in at least one case (modes with portal locked balls + thor or iron man mb). Do any of the others?

Off the top of my head, I don't believe they do (though I'm not 100% on every game):

Iron Maiden:
Can't combine trooper and mummy (to the point that if you set up both such that they could start with a single shot, it starts a 4-ball trooper instead). Can't stack either of those with Aces or Rime. Cyborg can't be started until modes and multiballs are done. Believe the same for Beast and Hills.

Jurassic Park:
Can't combine T-Rex or Raptor. Nor Chaos, right? I don't believe believe you can stack in mini-wizard modes either (King of Island, Visitor Center). Is there anything else? I haven't played this regularly in years or on latest code.

Godzilla: Can't combine bridge, tank, godzilla, monster zero, terror, or planet x.

Did I miss any obvious cases? Edge cases? Either way, for a designer of four games with a lot of multiballs across them and very limited multiball stacking, it seems like a clear rules design decision if not general philosophy. I've heard discussion from time to time about what characteristics make a Keith game a Keith game, but don't recall anyone ever mentioning this.

Lots of other games allow multiball stacking and lots do not. In some that do, it can be a key strategy (TWD and BSD are two off the top of my head that come to mind). Wondering if this has occurred to anyone else before about Keith's game or any thoughts about it now if not.

It's not. I was joking.

Totally agree. I think defaulting to allow most any multiball to stack usually creates a mess.

Realizing with Elwin it's nearly to the other side of the spectrum was kind of a "huh, that's interesting moment" for me.

Reflecting further, I think a sweet spot is generally when it is a challenge to set up the conditions to be able to add a second multiball to a first, such that when you do it creates an excitement moment, adds significant value, but isn't gamebreaking. Thinking through the Elwin games, I would say that we've yet to see that (except perhaps the Jurassic Park edge case).

Some of the Lyman examples are good representations of this. Maybe we'll something like this from Keith in a future game. I love his games/rules, so it's not like they are lacking for typically preventing multiball stacks. But it could be interesting, and I'd be curious to see how what kind of execution he'd cook up because I bet it would be cool.

Yeah, I answered the silly subject line question of thread. The rest of the content was what motivated and the post and I actually find interesting.