The LGP-30 has one conditional branch instruction, ‘T’, which normally tests the sign of the accumulator. But it has a variant form: if the sign bit of the instruction word is set (‘−T’), and the front panel TRANSFER CONTROL switch is set, then the branch is unconditionally taken.
This variant instruction form appears once in the game. In the normal case, a player using a simple strategy (take another card if ≤16) will quickly be in the hole. But if the TRANSFER CONTROL switch is set, they'll be ahead.
I don't have my notes handy, so my description of how this works may be slightly wrong.
The game has no seed for its pseudo-RNG; from a fresh load, if the player makes the same choices, the computer deals the same cards. (I can't think of any way to implement a changing seed on the LGP-30, other than asking the user to enter one.)
The game has a table of cards, indicating whether each card has been dealt or not. To deal, it pseudo-randomly selects a card, and checks whether it has been dealt already; if so, it tries again. (Yes, this is slow.) When all cards have been dealt, it clears the table to ‘open a new deck’.
When the program starts, it initializes the deck, unless the TRANSFER CONTROL switch is set. If the switch is set, the game starts with the deck table as loaded from paper tape. That (if I remember correctly) marks two aces as already used, and that is enough to skew the game play in the user's favour.
¹ ftp://ftp.informatik.uni-stuttgart.de/pub/cm/lgp30/