Regarding hockey player Teddy Green's $1969$ head injury, Newsweek stated:

$$Players will not adopt helmets by individual choice for several reasons. Chicago star Bobby Hull cites the

simplest factor: "Vanity." But many players honestly believe that helmets will cut their efficiency and put

them at a disadvantage, and others fear the ridicule of opponents. The use of helmets will spread only

through fear caused by injuries like Green's $-$ or through a rule making them mandatory.... One player

summed up the feelings of many: "It's foolish not to wear a helmet. But I don't $-$ because the other guys

don't. I know that's silly, but most of the players feel the same way. If the league made us do it$,$ though,

we'd all wear them and nobody would mind."

Draw up a table to represent a game to explain why players were both reluctant to wear helmets $($unless

mandatory$)$ but also OK with them being mandatory. Suppose one player is deciding whether to wear a

helmet $($before required$),$ and the $$other player$$ is what everyone else will do $($wear a helmet, or not$).$

What is the rational decision and why? What sort of game is this?