The rule is simple: a game qualifies when at most one person at a time needs to see something private. Charades shows the word to the actor, Taboo shows the card to the clue giver, and Wavelength shows the target to the Psychic and then moves on.
A handoff screen does the rest. Between turns the phone shows nothing but whose turn it is and who to give it to, so the only moment a secret could leak is covered by a screen that is deliberately blank.
That rules most of the list out. Psych and Scattergories need everybody writing in secret at once, and Skull and Dixit deal you a hand you hold all game — neither survives a screen the whole room can see over your shoulder.
The four that pass around a table
Questions about One phone games
Do we still need a room code?
No. Pass-and-play opens from the game’s own card and runs entirely on that one device — you type the names in once, and the table is remembered for next time.
Which games cannot be played this way?
Anything with simultaneous secrets or a private hand. Psych and Scattergories have everybody writing at once, and Skull and Dixit give you cards you keep, so a shared screen would show them to the room.
Do these four also work with a phone each?
All four run as an ordinary room as well. One phone is an option rather than a limitation, and it exists for the table where three people’s batteries have already died.
Which suits a table of four?
Bowl of Nouns and Charades both start at four and split into two pairs. Wavelength and Taboo seat two, but below four they become a co-op and a challenge ladder instead of team games.