When is ball hockey not ball hockey?

Ball hockey usually is a description of where you are playing the game, whether it be street,  road, deck, ground, and even beach hockey.

That sounds like any surface goes. Any guidelines?

The Canadian Ball Hockey Association (CBHA) states that any size or type of non-slip flooring  can be used as a playing field. The Niagara Ball Hockey Club sports two outdoor rinks with a sturdy  plastic grid overtop the cement surface, allowing for drainage and a more pleasant surface for 4 year  old players to land on!

What size ratio of playing space to number of players is recommended?

CBHA provincial, regional and national events are held in full sized hockey arenas about 200  feet (60.96 meters) long by 85 feet (25.9 meters) wide.

Each team has 6 active players including the  goalie at any one time. Smaller playing space uses fewer players as well as fewer rules omitting the  customary floor markings. Competition floor markings involve goal lines, goal creases, blue lines,  centre line, face-off circles and neutral zone face-off dots.

It sounds like a good training ground for ice hockey players.

The same basic array of rules in place: face-offs, penalties, offside, icing (flooring in this case),  floating blue-line and how to score a legal goal. Ball hockey gives maximum exposure to the game of
hockey in general without the cost or risks usually involved.

Do you use rotation of players like in ice hockey?

Extra players are on the team bench outside the playing surface. They switch on and off the  floor during play keeping the momentum of the game or at stoppage of play.

What gear do I need?

A ball and hockey stick. The physical contact allowed is similar to what is permitted in  basketball. The low-bounce type of ball typically used enables players to wear lighter weight protective gear than is used for protection against an ice hockey rubber puck, shin guards are likely the soccer type. Often a league will require gloves, helmet with full face mask, jock/jane straps, approved stick and shin pads. The hockey net is 6 feet (1.83 meters) wide by 4 feet (1.22 meters) high.