Trump Card Games Explained
A trump suit beats every other suit. Games differ mostly in how the trump is decided, and that changes everything.

Fixed trump
The same suit is always trump. Call Break and Spades use spades.
Chosen openly
A player names the trump. In Court Piece the caller chooses after five cards; in 56 the trump is part of the winning bid.
Hidden trump
The bidder places a card face down; only they know the trump until someone asks for it. This is the heart of Kerala's 28, 29, 304 and Thuruppu 40 (thuruppu means trump).
Set by the first cut
In Mendikot's cut hukum, the first card played by someone who can't follow suit decides the trump.
No trump
Hearts has none, and 56 allows a no-trump (NT) bid.
FAQ
What does thuruppu mean?
Trump, in Malayalam.
Which card games have a hidden trump?
28, 29, 304 and Thuruppu 40, among others.