As defined by Culbertson, an honour trick was the basic unit of defensive value. The overall value of a hand was the total number of honour tricks in each suit:
A-K two honour tricks.
A-Q one and a half honour tricks.
A-K-Q three honour tricks.
K-J-10 one honour trick.
K-x, Q-J-x half an honour trick.
In addition ‘plus values’ were deemed to be worth approximately one quarter of an honour trick. These plus values were: any queen that was not a singleton, any jack supported by another honour (but not a doubleton combination nor in a suit holding of A -K-Q-J), any singleton or void (but not more than one).
High Card Points are an older valuation method than Honour Tricks and after Culbertson’s influence on the bridge world waned, few players continued to use Honour Tricks as their main valuation method.