(A2A) The answer to this has changed over the course of history.
In every Tarot deck inspired by the Hermetic Order of the Golden Dawn – including, most importantly, the Rider Waite Deck – Tarot Key 11 is “Justice.” However in every other deck, including every deck devised before the Golden Dawn, Tarot Key 11 is “Strength.”
Confusingly, the Crowley Thoth deck, which undoubtedly is GD-inspired in part, has its equivalent of “Strength,” i.e. “Lust” as number 11, and the counterpart of “Justice,” i.e. “Adjustment” as Key 8. This is not, as some believe, because Crowley was using his ipsissimus super-powers to change the order of these two trumps, he was simply keeping the numbering found in ancient tarot decks.
VIII Adjustment, in the Crowley Thoth Deck. Numbered 8, but nevertheless attributed to Lamed and Libra all the same.
The reason there is any confusion at all is that the GD came up with the idea that if Keys 8 and 11 were Strength and Justice respectively, they would correspond to Leo and Libra, and if you put the Fool at the head of the Tarot Trumps, the whole sequence would qabalistically map onto the 22 letters of the Hebrew alphabet. Hence the innovation was made by the GD in making Justice number 11: Crowley just changed the numbering back – although he did retain the astrological signification.
Source: Alex Sumner’s answer to What tarot card is number 11? – Quora