Goal Line Technology
A year after Hawkeye - a British system - made its debut in the Premier League, German-manufactured GoalControl will become the first system to assist referees at a World Cup. Not all of the 32 referees at the tournament have used the goal decision system before, but English whistler Howard Webb says using it at the Confederations Cup in 2013 was a "good experience" and a "welcome addition".
While that tournament threw up no goalline incidents for GoalControl to ponder, the system - which like Hawkeye uses 14 cameras placed high in the stands to track the co-ordinates of the ball - has been rigorously tested. Barring a major mishap, each time a ball crosses the line in Brazil, the referee's watch will vibrate and signal a goal.
Vanishing spray has been used in Brazil and Argentina for several years and disappears after a minute. Armed with a can of 'vanishing spray' in a holster attached to their shorts, referees will spray a spot around where the ball should be placed at free-kicks near the penalty area, and a line for the defensive wall to stand behind after pacing out 10 yards. The water-based substance disappears from the turf after a minute, so there is no danger of the Maracana pitch looking like a toddler's nursery creation. It will also make its debut in the Champions League next season.
The heat and humidity in some World Cup venues has prompted Fifa to take action by calling for cooling breaks during designated matches that will afford players three minutes in each half to take fluids - stoppages that could see some broadcasters run 30 seconds of commercials.
Whether a game qualifies for a cooling break will be decided an hour before kick-off when Fifa's venue medical officer will consult the Wet Bulb Globe Temperature, a composite measure used to estimate the effects of such conditions on humans. If it reads over 32C, it is likely players will be allowed to take on fluids after both 30 and 75 minutes, but the match clock will not stop