Furiten question

[Senechal]

Genbutsu is the general term for 100% safe tile, thus making genbutsu-kuikae the rule that allows swapping out everything.

Calling 1+23s, throwing 1s, or 1+11s, throwing 1s. There is no way for anyone else to win off of it.

It's considered too cheap to allow in cash games, but in competitive play, it seems to be tolerated, more than anything. This is one of the things that has to be verified when playing in a new circle of players.

Kuitan/atozuke >> akadora presence >> kuikae options as mentioned above >> kan-dora flip rules >> cumulative/multiple yakuman >> ankan-kokushi. Their relative importance is as indicated, if money is at stake, there are additional things to add to that list.

[Masa]

There are a lot of unspoken rule(To whom ? it depends)
When I played with my friend, we confirmed standard rule for "me" but we forgot to confirmed " No Tsumo-pinfu"
I declared "Tsumo-pinfu-dora2", but it was "Tsumo-dora2" For him it was standard but for me not.
It is important to confirm the rule anytime with detail eye.

[Barticle]

"Pretty standard" is important word. "Kukae nashi" includes 2 things.
"Genbutsu kuikae(exchange same tile)" and "Suji kuikae". Standard one is both are not allowed. but sometimes "Genbutsu kuikae" only not allowed.

The PS3 game Mahjong Haoh: Dankyuu Battle 3 allows you to specify both or either. I think that's the only game I've encountered with those options.

So, I was looking into the term Genbutsu. The standard dictionary definition is "actual article" and (unlike Anzenpai) nothing about "safety" - I think in mahjong it just means "the same [tile]". In the context of defence it refers to a tile which you can discard safely against another player because they've already discarded the same tile (therefore furiten). With Kuikae it refers to calling 7 with 77 and discarding another 7 or calling 4 with 56 and discarding another 4.