Frisbee at highway speed...
5 players are lined up as a human wall. 14 meters away a member of the opponent team is just throwing a disc travelling at over 120 km/h (70 mph) towards your team.

Your team now has to stop the disc and catch it with one hand. The team member who succeeded in catching the disc makes him/herself ready to throw, as the other team prepares to make an attempt to catch the throw. This is guts.

The disc you use is a Wham-O "Pro Model" frisbee, that's nowadays produced especially for guts...

Your team scores a point when the other team fails to catch one of your throws. If a team fails to make a clean catch, it is allowed to catch a rebound, as long as the disc has never been touched by more than one body part simultaneously.

Or when the other team misses their throw so it passes your team too high,too much to the side or when it doesn't pass your team at all (i.e. hits the ground in front of your team).

Guts is normally played in best of 3 or 5 sets to 15.

The best players are not necessarily the fastest throwers, even though the disc speed of course matters alot.

But the hardest throws to catch are the ones that are thrown at such angle and spin that they get the "rapid dive effect", i.e. just before the disc reaches the other team, it takes a very sudden turn downwards.

 WFDF Official rules
 Guts Players Association
 Early history in Eagle Harbor