This is a strictly upgraded Melange Mining Corp. Coming at a rez cost of 0 compared to 1, it yields 6 credits instead of 7. This makes it an even gain on its first use after rez; additional uses will yield one less credit compared to Melange, if you can manage it. Each use will additionally allow the corp to remove 1 Bad Publicity, which has been a rare effect up to this point. To cap it all off it has a trash cost of 3, raised from 1.

Liked your review. But "strictly upgraded" is an exaggeration. —
It's "strictly" an upgrade~ish if you're in Weyland. If you're not in Weyland, it's a similar effect to Melange at 1 Inf a pop. If you're removing 1 Bad pub each time you fire this thing, then you probably don't care that the subsequent uses gain 1 less credit than Melange. The +2 trash cost is also welcome. If there's no bad pub to remove, or if you're not in Weyland, then there's still an argument to be made for Melange. —

I usually slot one of these in my Jinteki decks because I found it very versatile and useful in several ocassions. For glacier or horizontal jintekis. By these days I use it for the following

  • Put a used Snare! in my hand. Install the same snare and an agenda.

  • Make the same trick with an agenda as Fetal AI or Obokata Protocol if I haven't avanced them yet. Or if I have just drawn the Mushin No Shin to play them next turn.

  • Put the Snare in your hand and make your hand more scary. Install ice in other places.

  • Avoid Femme Fatale tokens. Install the same ice or another one.

  • Remove a Mwanza City Grid that has been already useful.

  • Just install scary ice in a remote server with already lots of ice without paying anything.

I haven't tried to export it to other factions yet, but the Jinteki mind games are more difficult to import and with a 3 influence is harder to justify.

Gatekeeper is strongest when it was rezzed this turn, so it would combo with cards that allow you to derez your own. Cards that help you get more activations from the rez strength ability are needed to help combo.

Bioroid Efficiency Research makes it so if the runner does break through, you get another shot at the rez strength.

Divert Power makes something cheaper while you get to trigger this rez strength again.

Test Ground allows you to fire the trash ability, derez Gatekeeper, and then re-rez Gatekeeper with unexpected strength.

Plus, Gatekeeper is cheap and might give you some recursion of used cards if you can catch the runner flat.

Is it for every deck? No. But it might have a place in some.

Great first review. You've highlighted —
some good combos. Just note that Bioroid Efficiency does not work as Gatekeeper is not a bioroid ICE. In addition, Blue Sun is also worth a mention! —

Rules doubt.

Does lucky charm also work for any subroutine (for example a wall of static or vanilla)? Or just things that say "end the run" that they're not from the corp?

Are subroutines card abilities?

Yes, that is correct. It can be used against WoS or Vanilla or any other normal (single) ETR sub. —

A weak but tenacious code gate for Weyland! I've seen a lot of this due to rampaging Hippos and hungry Maxxes with Spoons destroying ice left and right, because this can't ever fall prey to those if it's correctly placed on HQ. Anywhere else and this is diet Enigma, so please don't do that.

This one REALLY hoses Anarchs running Black Orchestra (aka all of them), they pay 3 to break and still have to hit the first sub to even get a look at HQ. It's a minimum cost 3 for pretty much every Decoder, which is solid for a 3 cost ETR. It slots in just about any Weyland deck that wants to discourage frequent HQ runs!

Nice! I never considered the fact that it's immune to cutlery and Hippo considering you can't break all its subroutines on HQ. —