The rules committee considered widening the playing field to "open up" the game, but Harvard Stadium (the first large permanent football stadium) had recently been built at great expense; it would be rendered useless by a wider field. The rules committee legalized the forward pass instead. Though it was underutilized for years, this proved to be one of the most important rule changes in the establishment of the modern game. Another rule change banned "mass momentum" plays (many of which, like the infamous "flying wedge", were sometimes literally deadly).