2008-09: Ludwig Karlsson skated in Sweden’s U20 SuperElit league as a 17-year-old — splitting the season between Linkoping’s U20 and U18 squads. In 23 SuperElit games he scored 5 goals with 7 assists and was +7 with 16 penalty minutes. Linkoping defeated Leksands before falling to Brynas in the playoff quarterfinals. Karlsson scored 4 goals and was +1 with 4 penalty minutes in five playoff games. In nine U18 games, including 2 playoff contests, he scored 4 goals with 5 assists and had 6 penalty minutes.
2009-10: Karlsson moved to North America to play for the USHL’s Green Bay Gamblers. In 58 games he scored 8 goals with 21 assists and was +15 with 16 penalty minutes. The Gamblers finished first in the East Conference and won the USHL’s Clark Cup. Karlsson scored 1 goal with 2 assists and was an even plus/minus with 2 penalty minutes in 12 playoff games. In March 2010 he committed to playing college hockey at Northeastern University in 2011-12.
2010-11: Karlsson returned to Green Bay for a second season with the Gamblers. He scored 13 goals with 25 assists in 56 games and was +8 with 14 penalty minutes. The Gamblers finished second in the Eastern Conference and lost to Western Conference champion Dubuque in the Clark Cup finals. Karlsson was -3 and scored 2 goals with 3 assists in 11 playoff games.
2011-12: Karlsson was Northeastern University’s leading scorer as a freshman. In 32 games he scored 10 goals with 16 assists and was +3 with 8 penalty minutes. The Huskies finished tied with Massachusetts-Amherst for eighth in Hockey East but missed the playoffs on tiebreaker criteria.
2012-13: After a sensational freshman campaign, Karlsson followed it up with an impressive start to his sophomore season before suffering a season-ending wrist injury in January. He played in just 17 games, posting 5 goals with 3 assists and finished -2 with 4 penalty minutes. His most memorable game was on November 10 versus Alabama-Huntsville when he netted a pair of goals in guiding the Huskies to a 3-0 victory. Karlsson signed a two-year entry-level contract with Ottawa as a free agent in July of 2013, foregoing his final two years of college hockey.
2013-14: Karlsson skated in eight games with Ottawa AHL affiliate Binghamton — spending most of his first pro season with the Elmira Jackals in the ECHL. He had no points nor penalties and was -3 in AHL play. Karlsson scored 11 goals with 13 assists and was -6 with 4 penalty minutes in 39 games for the Jackals. Elmira missed the ECHL playoffs; finishing third in the three-team Atlantic Division. In July 2014 he was acquired by Dallas along with Jason Spezza in a multi-player trade.
Karlsson is a dynamic winger blessed with size who can play either wing; possessing soft hands and handling the puck with poise. Still fairly raw in terms of development, he has been able to score at the ECHL level but is a still a work in progress in other parts of his game and has yet to have that same type of production in a handful of AHL games. One of Karlsson’s best attributes is his shot. He possesses a hard, accurate shot with a quick release. Karlsson skates with long, smooth strides and has really nice edges. He does a good job of consistently keeping his feet moving – an area that vastly improved this season. He possesses quick feet and good acceleration as well. Karlsson must use his large frame more effectively to get inside positioning on opposing defenders. More of a skill player than a true power forward he must be more active in tight spaces and make quicker decisions if he is to move up the ranks.
Karlsson attended his first training camp with Dallas before being assigned to AHL affiliate Texas and ultimately starting the 2014-15 season with the ECHL's Idaho Steelheads. He appeared in two AHL games with Texas in late November before being returned to Idaho. After leaving Northeastern following his sophomore season Karlsson is now in the second year of his original two-year entry-level contract. There are some elements of his game to like but the fact that he is still toiling at the ECHL level makes it unlikely he will be at the NHL level anytime soon.