Competition at the Parapan American Games opens Saturday in Toronto with some 1,600 athletes competing in 15 sports. From boccia to goalball, many of the events are unique to para-competition. Here is a quick guide to some of those sports:

BOCCIA

This distant cousin to lawnbowling and bocce was originally intended as a sport for those suffering from cerebral palsy, but today is open to all athletes using a wheelchair. Played on a smooth, flat surface, boccia features both individual and team events. In both cases, players aim to place the six game balls as close as possible to a white target ball known as the jack. Para-athletes can push, kick or propel the balls with assistive devices depending on their level of physical mobility. The individual or team with the number of balls closest to the jack at the end of the match wins the game. Boccia veteran Marco Dispaltro was Canada's flag-bearer at the Parapan Games opening ceremonies. The 48-year-old former wheelchair rugby player said boccia is a more strategic sport akin to golf or curling.

FOOTBALL 5 A SIDE

This relative newcomer to the Parapan Am Games is soccer for the visually impaired. Four of the players on a team, who have varying degrees of visual impairment, wear eyeshades to minimize any unfair advantages. The fifth player can be fully or partially sighted and always serves as the goalie. Each team also has a guide standing off to the side to offer directions as needed. Players spend each 50-minute match trying to kick an audible soccer ball into the opposing goal.

FOOTBALL 7 A SIDE

This event, returning to the Parapan American Games after an eight-year absence, is a modified form of soccer for athletes with cerebral palsy or other neurological disorders. Playing on a smaller field than mainstream soccer pitches, teams consist of six kickers and one goalie. Certain moves prohibited in able-bodied soccer are permitted in seven-aside, such as offsides and one-handed throws to return the ball to the field. Seven-aside athletes are divided into four classifications, dubbed FT5 through FT8, based on their degree of physical impairment. Each team must have at least one FT5 or FT6 player on the field at all times and can never have more than one FT8 player on the pitch.

GOALBALL

This game, originally designed as a rehabilitation exercise for blinded veterans returning from the Second World War, is played today exclusively by athletes with a visual impairment. Two teams of three players each don eyeshades to ensure a level playing field, then square off on a court equipped with tactile markings and goal lines. The objective is to roll the ball, which has bells inside, into the opposing net. Because players rely so heavily on the sound the ball makes while it's in play, audience members are asked to remain mostly silent through the match. They can, however, feel free to cheer for their team when someone scores a goal.

POWERLIFTING

While able-bodied weightlifting sees people displaying their strength from a standing position, the para-sport version is for those who can't be on their feet. Instead, powerlifters essentially perform extreme bench presses. Athletes lie flat, lower a bar to their chest, then see if they can heft enough weight to secure them a medal. The sport is open to athletes with any type of physical disability that would prevent them from taking part in mainstream weightlifting.

SITTING VOLLEYBALL

This adapted version of mainstream volleyball sees teams of six face off across a net from sitting positions on the floor of the court. Players must serve the ball across a net that's at least a metre high without letting it touch the ground. Sitting volleyball players are classified as either "disabled or "minimally disabled." To ensure fair play, only one minimally disabled player is allowed on the court at a time.

WHEELCHAIR BASKETBALL

This marquee event sees players follow most of the rules from mainstream basketball, but with a few key differences to accommodate their wheelchairs. No player can push the wheels of their chair more than twice before either throwing or passing the ball. Players are assigned a classification of between 1 and 4.5 depending on their degree of physical impairment, and no team is allowed to have more than 14 points on the court at any one time. Canada is a strong medal contender in this sport. The men are looking to defend their gold-medal title from the 2012 Parapan Am Games in London, while the women are hoping to duplicate last year's world championship victory.

WHEELCHAIR RUGBY

This sport is returning home to the country of its origin. Wheelchair rugby as we know it today was developed by a group of quadroplegics from Manitoba looking for an alternative to wheelchair basketball. The sport they devised sees players carry, dribble or pass a ball towards the opposing team's end. A player must have two wheels on the goal line in order for a point to be counted. Wheelchair rugby players all have limited to no function in three out of four limbs. Similar to wheelchair basketball, rugby athletes are assigned a score of 0.5 to 3.5 based on their degree of physical limitation. No team of four can have more than eight points on the court at once.