McDonald was known primarily as an offensive player with a hard shot.
His wrist shot was considered to be effective, and his scoring exploits in junior hockey earned him the nickname "Machine-Gun Lanny".
Red Kelly, McDonald's coach in his first NHL seasons, recalled that he was impressed with his young player's skill handling the puck and defended McDonald critics who wanted him moved out of Toronto due to his early struggles.
In his NHL career, McDonald led his team in goal scoring six times: 1976–77, 1977–78 and 1978–79 with Toronto, 1980–81 with Colorado, and 1981–82 and 1982–83 in Calgary.
He was also a physical player, willing to play a hard-hitting style in the corners.

As age and injuries took their toll, McDonald's role with the Flames changed.
His playing time decreased in his later years as he was no longer counted on to be the team's primary offensive threat.
Often left out of the lineup in his final season, McDonald was expected to provide a boost to the team when he drew into the lineup.
He was counted on to provide a veteran presence and to act as a mentor for the team's younger players.
McDonald was known primarily as an offensive player with a hard shot. His wrist shot was considered to be effective, and his scoring exploits in junior hockey earned him the nickname "Machine-Gun Lanny". Red Kelly, McDonald's coach in his first NHL seasons, recalled that he was impressed with his young player's skill handling the puck and defended McDonald critics who wanted him moved out of Toronto due to his early struggles. In his NHL career, McDonald led his team in goal scoring six times: 1976–77, 1977–78 and 1978–79 with Toronto, 1980–81 with Colorado, and 1981–82 and 1982–83 in Calgary. He was also a physical player, willing to play a hard-hitting style in the corners.
As age and injuries took their toll, McDonald's role with the Flames changed. His playing time decreased in his later years as he was no longer counted on to be the team's primary offensive threat. Often left out of the lineup in his final season, McDonald was expected to provide a boost to the team when he drew into the lineup. He was counted on to provide a veteran presence and to act as a mentor for the team's younger players.
Lanny McDonald