Plot Armor

Not to be confused with taking the script and wrapping it around your body.

If someone, often a main character, should have died but didn't, won the big game when all seemed lost, or won in any other context that's suspiciously useful to them, that's Plot Armor in action. Plot Armor is what protects a plot-important character from a failure that they deserved or logically should've gotten so that the plot doesn't go in the wrong direction. Ex Machina UnTrashes such as Plot Ex Machina are commonly played to subsequently play Plot Armor, but non-Ex Machina UnTrashes like Set Destiny can be considered Plot Armor as well.