EGO is a game mechanic in Duke Nukem Forever. It serves as Duke's health bar. Whenever Duke is hit by enemy fire, his EGO decreases until Duke enters the danger phase. After avoiding damage for a certain amount of time, Duke's EGO will start recharging. During the danger phase, player's sight is lowered as a loud heartbeat is heard. In this form, Duke's EGO will start regenerating sooner. As soon as the player enters the danger phase, they should immediately start looking for cover, or just start avoiding enemy fire if there is no cover, until their EGO recharges to maximum. On each level, player can increase Duke's maximum EGO by interacting with object and items for first time (ex. magazines, toilets, computers, gym). Killing bosses will also give an EGO boost.
NOTE:Playing pinball, pool and video games will give the largest EGO boost.