ED-E的第一站是芝加哥的英克雷隐藏前哨站，在这里进行升级和维修。After leaving the Chicago outpost and continuing it's journey, ED-E was found by Tommy who later convinced his dad to take him in. It was here that ED-E recorded Tommy finding him and moments with Tommy's family. After being under Tommy and his father's care它接着穿过了莫哈维废土，在那裏它被放了两次冷枪，在严重受损但还能保持状态的时候奔向了普瑞姆，被莫哈維快遞的信使捡到拿給约翰逊·纳什。老纳什修理技能不够，就一直把ED-E摆在桌子上，直到邮差经过，修好之后把它变成了同伴。
With the Lonesome Road add-on installed, ED-E can be used to create items as if it were a workbench or reloading bench, through dialogue. This option will already be available even before Lonesome Road has begun.
ED-E can be further upgraded by finding five circuit boards in the Divide:
Rank 1 - Weapon maintenance function: Access to a daily dialogue option allowing ED-E to instantly restore the condition of the Courier's currently equipped weapon by 25%. (This can be increased to 35% with skill check, after obtaining rank 2).
Rank 2 - Energy/microfusion cell production: Access to a daily dialogue option allowing ED-E to produce a number of energy and microfusion cells. Also, through dialogue and skill checks, ED-E can produce more cells per prompt, or be made to produce flamer fuel or satchel charges (which share the same once-per-day cooldown as the energy and microfusion cells).
Rank 3 - Increased DT: +2 DT for both the Courier and ED-E.
Rank 4 - Beam damage bonus: +5 to beam weapon damage; affects the same list of weapons affected by the Laser Commander perk.
Rank 5 - V.A.T.S. accuracy bonus: Chance to hit targets in V.A.T.S. increased by 5%.
第一次碰到ED-E的时候，ED-E在右边有一个特别的标签＂我的孩子是一个罗斯福学院的优等生＂这是位於Fallout 3的地點。在特别标签的另外一边，是一个＂伟大中西部＂伊利诺斯州2062年的照牌，读作＂2ED-E59＂。数字比字母遭受了更严重的磨损和退色，所以乍看上去像是读作＂ED-E＂。这些细节在孤独之路里得到了解释，where the duplicate version mentions that the original had to stop in Chicago for repairs and visited a family along the way.
无论是兄弟会还是天启追随者升级了ED-E，它都会发生变化，如果是天启追随者升级，装甲不会变，但是弹道会变成外星枪一样的蓝色。Also, when in combat its laser will sound the same as a Tesla cannon and outside of combat it will make a buzzing-like sound as well. 兄弟会升级之后ED-E的盔甲会更亮，但无论是哪种升级，都会移除他身上的贴纸和车牌。
If ED-E is ever frenzied, it will become hostile if dismissed as a companion and returned to Primm. The only exception is if it is sent to be upgraded. After a few days, ED-E should be willing to go with the player again, found roaming around Primm instead of inside the Mojave Express.
After having completed the game and the "ED-E My Love" quest, ED-E will give an account of what happened after the events of the game; however, its account will be spoken using its signature beeps, so general subtitles must be enabled in order to understand them; luckily they can be applied by pausing during that screen.
ED-E might strafe side-to-side if multiple enemies are in sight. Although it seems tactical, it won't help if the enemies have firearms.
Powder Gangers may comment that they envy the Courier for having a "flying" robot on their side.
The four versions of ED-E (not working, working but not upgraded, upgraded by the Brotherhood of Steel, and upgraded by the Followers of the Apocalypse) all have different console IDs.
The Courier seems not to understand ED-E's beeping. However, during Lonesome Road (add-on) they understand ED-E quite well. Regardless, it does not change the way the Courier interprets ED-E's beeping, unless one of the Lonesome Road linked upgrades or audio logs is selected, resulting in <happy beeping> or <makes beeping sounds>.