Lui started the season playing for the Tigers' NYC team. He made his NRL debut in Round 23, in a 56-10 win over Cronulla Sharks, and played 2 further games near the end of the season. Returning to the Wests Tigers' NYC team, he played in the team that lost the Grand Final to Melbourne Storm, scoring a try in the second half. At the end of the season, Lui was named in the Toyota CupTeam of the Year.
2010
In March, Lui re-signed for the Wests Tigers to the end of the 2012 season, with coach Tim Sheens describing him as, "an integral part of the team." Lui was named to start the season at halfback, but suffered an injury in round 2. Upon his return, in round 10, he scored his first try. Lui played 17 games in 2010, improving as the season progressed, with one newspaper describing his last game of the year, in the preliminary final, as the, "best game of his career."
2011
Lui played in 23 games in 2011, scoring 5 tries. From round 17 onward, Lui was halfback as Wests Tigers won nine games straight, eventually losing in the semi-final. Lui was said to be, "the first halfback in years to properly gel with Benji Marshall." At the end of the 2011 season, Lui was released from his contract with the Wests Tigers after he was charged with assaulting his partner, Taleah Rae Backo, in her North Strathfield home. He had previously been charged with similar offences after an incident at the end of 2010 season, with those charges being dismissed in April. He pleaded guilty to assault occasioning actual bodily harm on his former partner and was placed on a two-year good behaviour bond and fined $2000.
2012
Lui signed a two-year contract to play for his hometown team, the North Queensland Cowboys. He made his debut for the Cowboys in Round 1, coming off the bench to play in the halves. The next few weeks Lui was pushed back to reserve grade to regain match fitness after his pre-season was hindered by a serious knee injury. He played in five games for the Northern Pride. Lui's 2012 campaign was cut short however after being suspended from playing any form of rugby league for the rest of the season after pleading guilty to an assault charge placed against him several months earlier. His ban was placed on him from Round 8. He was free to start playing rugby league again in the 2013 trials.
2013
Although being suspended for a majority of the 2012 season, Lui retained his job at the North Queensland Cowboys and remained training with the club full-time for the rest of his suspension. Before his suspension, Lui was regarded as a possible future representative player and was included in the 2011 Emerging Origin Squad for Queensland.
2014
In February 2014, Lui was a member of the Cowboys victorious Auckland Nines side. On 2 September 2014, Lui agreed to a one-year contract extension with the Cowboys, keeping him in Townsville until the end of 2015.
2015
Lui spent the majority of the 2015 season playing for the Cowboys' feeder side, the Townsville Blackhawks. On 3 October, Lui signed a one-year deal with the Salford Red Devils, reuniting him former coach Tim Sheens.
2019
He has signed on loan from the Salford Red Devils until the end of the 2019 season, and has signed a two-year contract with Leeds from the 2020 season.
Statistics
NRL
Personal life
Phillip Lui, Robert's father, played for Queensland A in the late 1980s. Former Cowboys' team mate and good friend Ray Thompson is godfather to Lui's son.
