Guts is a statistic that plays a key role in 1-800 Regime Change. If you’ve played a recent tabletop game you’ll probably have noticed that almost everything includes a mechanic that allows a player to reroll a bad roll. Guts is that, but on a per-die basis, meaning that instead of rerolling everything they may reroll one die (before explosions, if appropriate).
The way Guts works is also somewhat similar to a buff in a video game, when one uses Guts they also get a status effect called “Pumped Up”. This gives them a +1 bonus to rolls on their next turn equal to the amount of Guts points they spent (multiple can be spent in a turn, and they can burn Guts for no reason other than getting Pumped Up).
This essentially serves as a pool of backup energy and luck for a character, when they use Guts they can get out of almost any situation.