The word gamesmanship is playable in Words With Friends™, no blanks required. Because it is longer than 7 letters, you would have to play off an existing word or do it in several moves.
Words With Friends™ Letter Score: 26
Highest Scoring Words With Friends™ Play In The Letters
Seven Letter Word Alert: (38 words)
ammines, amnesia, enigmas, geishas, gnashes, haemins, hamming, heaping, hemming, hipness, impasse, inseams, magpies, manages, mashing, massage, massing, meshing, messiah, messing, miasmas, mishaps, misname, mispage, mispens, pansies, passage, passing, phasing, saphena, sashing, seaming, shamans, shaming, shaping, shipman, shipmen, smegmas