Force field

Force fields are invisible electric fields set up by The Capitol that are used to prevent tributes from escaping the arena, and any other places so they won't run away from The Games.

Appearances
The first time that Katniss ever comes in contact with a force field is on the Training Center's roof with Peeta, who shows her how the force field works by putting his hand onto it and feeling the sharp zap that follows.

Haymitch Abernathy used a forcefield in his arena to defeat the other finalist in The 50th Hunger Games by letting her drop her weapon onto it and watching it rebount and come back and lodge itself in her head.

In the training center while Katniss was preparing for The 75th Hunger Games, Beetee and Wiress pointed out the weak spot in the force field that is inbetween the gamemakers and the tributes to her, which is a small wavering square in the air, revealing the invisible force field. Katniss thinks that this force field is in place because of Katniss's Private session the year before.

In The 75th Hunger Games, Peeta almost died from getting shocked by a force field, but luckily Finnick revived him. Blight, the male from District 7 also hits this force field, but Finnick isn't present to revive him so he dies. Katniss uses the wire Beetee planned for a trap and a Gamemaker-created lightning bolt to destroy the forcefield arenain The 75th Hunger Games. This was done by firing a knife with Beetee's wire attached to it with her bow into the weak spot - the chink in the armour of a forcefield.