Whilst with Motherwell Law was named in the PFA Scotland Team of the Year for season 2012–13 and the following summer joined Rangers.

[8] Law had to wait until his third senior season to score his first goal for the Blades coming in a second round League Cup tie at MK Dons on 28 August 2007.

[19] In October 2008, Law was again signed on loan at Bradford City, as cover for Joe Colbeck, who was injured in a victory against Grimsby Town.

[20] His first game during his second spell was a day later and ended in a 1–0 victory against Bury at Valley Parade, with Law nearly scoring in the first half.

[23][24] Law returned to Bramall Lane at the end of the season having made 29 appearances for the Bantams but was placed on the transfer list as Sheffield United sought to trim their squad.

[27] Law went immediately into Rotherham's first team after impressing in pre-season, making a huge impact to the squad and endearing himself with the fans.

"[citation needed] On the strength of this, Middlesbrough reportedly placed a late deadline day bid, but this was rejected by Rotherham.

[28] After topping the list of assists in League Two consistently since the start of the season,[citation needed] Law scored his first goal for Rotherham on 26 September against Barnet.

[31] In his first season, Law, along with two other Rotherham United's player, Ian Sharps and Adam Le Fondre, named the 2009–10 Football League Two Team of the Year.

[52] At the end of the 2012–13 season, Law, alongside teammates Shaun Hutchinson, Darren Randolph and Michael Higdon, was named in the PFA Scotland Team of the Year 2012–13.

[61] In January 2014, Manager McCoist said he didn't have any regrets about signing players in the summer, Law being among them, despite a deterioration of the financial situation at Rangers.

[62] Law scored two goals on his debut, playing as a trialist, in a Challenge Cup win over Albion Rovers.

[64] Since joining Rangers, manager McCoist says Law is responsible for helping the club by bringing "real calmness" and "an attacking edge".

[67][68] Law started for Rangers in the 1–0 loss to Raith Rovers in the 2014 Challenge Cup Final, where he missed a number of chances.

Under new manager Mark Warburton, Law made a strong start to the 2015–16 season and scored a goal in a 3–0 victory over Livingston on 12 September 2015.

[73] He immediately became a fan favourite, scoring on his debut against Carlisle United[74] and netting many other crucial goals against the likes of MK Dons[75] and Notts County.

Despite this, Law still scored some crucial goals in his appearances, such as an equaliser (as well as two assists) against League One Gillingham in the second round of the FA Cup.

On 30 January 2021, it was announced that Law would join USL Championship side Indy Eleven ahead of their 2021 season.

[82][83] On 21 July 2022, Law was transferred to USL Championship side Tampa Bay Rowdies in exchange for Juan Tejada.

[86] Following a stint as player-coach for Huntsville City, Law returned to the Tampa Bay Rowdies on 27 July 2023 to serve as the club's head coach for the remainder of the 2023 USL Championship season.