Apparently the wizard's field of protection kept everything but magic from passing through.

He had always thought that Argo's magnetic fields kept all the dangerous stuff away.

Of course, protective fields kept the smoke from touching anything on the island.

On entering first field keep forward along right edge.

Fortunately, the dampening field would keep him from attempting it on his own.

The field was gravel, tamped hard and kept clean and level.

The field kept her feet warm and dry.

The little field would slow time almost to zero within its limits, and keep any damage from occurring while he worked.

A rainy field kept both offenses quiet for most of the night.

In the process, the margins move farther out, and the field that is opera keeps expanding.