Sonic Speed DX (ソニックのスピードDX Sonikku no Supīdo DX?) is a mobile phone game released as part of the Sonic Cafe service offered by Sega, and is the third version of a line of games whose predecessors were Speed and Speed DX. This game is a card game where player(s) choose a character out of Sonic, Tails, Knuckles, Amy Rose, Dr. Robotnik and Shadow, then either play a 1P game against the computer or as a 2P game against each other. High-scores can be logged on the high-scores server. There is also a tutorial mode to explain the game's rules and a cut-down graphically version of the game for the lower-spec phones.