Considering that there's rarely a need to run and the other classes can run well enough, the Thief is truly useless the entire game.
Fighter/Knight - Too expensive and equipment dependant
Thief/Ninja - Not worth being handicapped half the game for a subpar Red Mage later
Monk/Master - No customization at all, pretty boring
Black Mage/Wizard - Offensive Magic sucks and I hate status magic
White Mage/Wizard - Items will do most of their work anyway and I hate dealing with limited MP
Red Mage - Has all the strengths and weakness of the BM, WM, and Thief rolled into one
Considering that there's rarely a need to run and the other classes can run well enough, the Thief is truly useless the entire game.
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