13 countries participated, 5 more than in 2011, including first-time competitors Finland, Germany, Israel, Serbia, Switzerland, and Turkey. Most games were held on the Onondaga Nation at the Onondaga Nation Arena and the newly-built $6.5 million Onondaga Nation Fieldhouse, although the Iroquois' games versus Canada and the United States were held at War Memorial Arena in Syracuse. Over 10,000 fans attended the gold and bronze medal games in the Carrier Dome.
The opening ceremonies in the sold-out War Memorial Arena featured a light show about the Haudenosaunee creation story and traditional dancing. After the Iroquois Nationals were not allowed to use their Haudenosaunee passports to travel to England in 2010 due to new security requirements, many international players were interested in getting their passports stamped by the Onondaga Nation. The documentary Spirit Game: Pride of a Nation explains the meaning of lacrosse to the Iroquois people and covers the Iroquois Nationals in the 2015 WILC, featuring brothers Lyle and Miles Thompson.
The teams were divided into 3 divisions, with the 5 highest-ranked teams placed in the Blue Division and the others being split into the Red and Green Divisions. In the Blue Division, the top two teams advanced to the semifinals, the third and fourth teams entered the quarterfinals and the fifth team was placed in the classification bracket. The top two teams in both the Red and Green Divisions entered the play-in games, while the bottom two teams were placed in the classification bracket.
Canada once again was undefeated in pool play, although they had a tough game versus the Iroquois. The Nationals lead 8–4 early in the third period, but were outscored 7–1 the rest of the game.
The gold medal game was close throughout the first half, with only two brief two-goal leads for Canada. Canada led 6–5 at the half, then the teams traded two-goal runs to get back to 8–7 in the early fourth quarter. Steven Priolo and Stephan Leblanc both scored in unsettled situations within a minute of each other for Canada to take command of the game with 10 minutes left.
Team Canada's Curtis Dickson led all scorers with four goals, including one open-net goal, and an assist. His teammate Mark Matthews had four assists. Randy Staats and Johnny Powless both had four points for the Iroquois.