Hanamikoji could be a good option.

Give "Love Letter" a try.

in Hive, there is no way a new player can challenge somebody who already knows the game + the movements of the insects confuses new players

do you know Set, it's not a strategy game but that's why somebody who's playing for the first time can challenge a more experienced player. No luck either.

I've recently discovered Ninjan ☞ https://boardgamegeek.com/boardgame/425254/ninjan basics are from rock paper scissors (so everybody is familiar with the dynamics) It adds another level to this base

Go might be a good option. It uses a simple square grid or checker board, and only has one kind of piece per player. The rules are super simple. Play time depends on the players' skill and the size of the board.

Also good is Pente, which uses the same pieces and board as 19x19 Go. It also has simple rules and is easy to learn.

Checkers is an option. I haven't played it enough to know how strategic it gets.

All of these are easiest to port if you have a board that rolls instead of folding.

Hive Pocket is fairly easy to learn, maybe strangers would be down to play. I would also recommend a magnetic set of backgammon or maybe mancala.

If space isn't limited, I really like Knarr. It's pretty short and easy to learn, but it does basically require a decently sized table.

Quatro or Quoridor. You can get a 3D printed travel version.

You might like the Pack O Game series, very small and portable. Hue would be a good one to check out but the rest are good too:

https://www.perplext.com/packogame/hue

Radlands. 2-player tower defence game. Minimal space required. Tight gameplay. I have the retail edition without the maps.

Cabo. Up to 5 players. Anyone can play it. From primary school kids to granny. Remember your cards and try to swap to get the lowest score.

I'm designing a micro dexterity game (6 pieces) that I think would work here:
https://github.com/s3rvant/boardgames/blob/main/Leap%20Frog/Rules%20v11.md

I'm still tweaking a couple rules to fine tune the feel I'm after though pieces won't be changing so I could send a set if interested in providing some feedback?

Mr. Jack Pocket is the ultimate short simple 2 player game. The depth of gameplay is much greater than the size of the game or ruleset.

Trying to squid games people OP?

"Taco Cat Goat Cheese Pizza" is a card game that's purely reaction based, and is very similar to "war" which you may have played with a standard deck of cards in grade school, but there are a few special cards to mix things up a little bit.

Since it's reaction-based, it's not very luck based and it's not very strategic (edit: oops you asked for strategy, my bad .. disregard?). After a round, everyone knows what the cards look like, so experience counts for very little as well.

And it's surprisingly fun. We laugh a lot. Pro tip: remove wedding rings.

You need a flat surface to play on.

https://dolphinhat.com/product/taco-cat-goat-cheese-pizza/

Reasonable options might be Cat Lady or Cascadia, maybe Codenames Duet and Welcome To.

I also second Splendor and Star Realms.

if you're looking for coap I'd recommend space team if you want frantic or hinabi if you like puzzles

If you're into dice games Quizz or Yahtzee could work.

Both are pretty portable. Quizz comes with its own box, and Yahtzee technically just needs five die (and probably some paper or a phone for scoring).

Scopa - easy to learn, hard to master. Quick, fun. And if you come across an Italian they'll likely already know how to play. Added bonus, some of the decks are gorgeous.

My goal is to have a game that I can carry around with me, walk up to people I meet in public, and ask them to play.

Is it just about portability or do you also need a small playing area?

I want the game to be strategic with minimal luck but simple enough that a first time player could reasonably win against someone experienced.

Those goals are at odds. If there's minimal luck, there's little room for the new player to win in a strategic game.

That being said:

• Azul can be quite portable (if you dump the box), but needs some playing space. It's vicious with two players, the more experienced player will usually win, but the rules are simple enough for a first time player to at least understand what happens.
• Onitama is chess-like, with simple rules and some randomization that prevents the need to memorize start sequences and the like.
• Arboretum is a tight battle with two players. You constantly need to worry which cards to play in order to gain points, which cards to keep in order to even be eligible for scoring and which useless cards not to drop, because they might be useful for your opponent.
• Kahuna is a bit older, with simple rules but some strategy.
• The Fox in the Forest is a two player trick taking game I found rather enjoyable (and I don't even like trick taking games).

Our portable goto is Star Realms, but other card-based games will work. Dominion comes to mind except for the deck size!

Splendor. If taken out of the box, it can be stored in a much smaller box. It is very easy to learn and a lot of fun for 2-4 players.

'Mastermind' is a peg-based two player game. Loved playing that when I was younger.

Heckmeck.

The version I have is in what I assume is German, but I'm pretty sure it has an English name. It's probably more luck than strategy, but can't possibly win without some sort of a plan. Roll some dice, decide what to keep, and get those worms!

Replacing the box with a bag would increase portability.

Nine Men's Morris or Reversi/Othello?