Scrabble

Percy: I will put my A down to make "A".

Jason: I will add to your "A" to make "AT".

Leo: I will add onto your "AT" to make "RAT".

Annabeth: I will add onto your "RAT" to make "BIOSTRATIGRAPHIC".

Percy: *flips the board

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(Had to check that word five times to make sure that was right.)