Luscombe was born in South Africa, but arrived in Wales as a teenager after being identified as one for the future by Graham Henry. Luscombe qualified through his Welsh-born mother. He made his debut against Scotland in 2003, but established his place in the squad after the last World Cup. Luscombe started against Scotland and Italy in the 2005 Grand Slam campaign before being sidelined by a hamstring injury. A similar problem ruled him out of the autumn internationals. Luscombe moved from the Newport Gwent Dragons to Harlequins in the summer.