Porter Gage grew up in a small farming settlement with his parents, watching them give in to raider demands without a fight. When he was twelve and they were raided once again he used this chance to run away from his home to avoid following in his parents' footsteps.
The next few years, Gage survived by taking odd jobs, doing what he could to earn caps. Later he turned to caravan and mercenary work; however he still saw people giving into raiders, and realized something about the raider way of life: he wanted to be one of them. After the raid of a settlement he had been residing in, he joined the raiders at 16 years old.
The first gang he joined was a decently sized group which apparently had a lot of strength, but wasn't using it wisely. Being young and naive, he tried to suggest things to try and better the gang. Eventually he was approached by his boss, Connor "The Harvester" (a name Gage thought was laughable), who listened to Gage much to the latter's surprise. After this, Connor would keep going to Gage for advice on his plans, telling him how much he trusted him which went straight to Gage's head.
After a year of working alongside Connor's gang, Gage and Connor decide to try and make peace with another nearby gang. Meeting on neutral ground, they worked out who would do the negotiating and what would happen if it went wrong. Gage volunteered to take point for the negotiation with three of their biggest crew mates backing him up, and he was chosen.
An hour into the negotiation, the rivals began to come around, saying the truce was in their best interest - however, before Gage knew it, there was gunfire and explosions. He began to panic, thinking that Connor would have to come bail them out. He soon realized that Connor had set him up for death. Connor, in Gage's mind, must have began to fear him, thinking he had "pumped" out all of the good information and that Gage would be after Connor's role. He used Gage as a distraction so he and his men could ambush both Gage and the rival gang. Gage survived the encounter and left alone.
Gage debated going back to his former boss and his gang with guns blazing and revenge in mind, but he knew that would lead to certain death. Instead he moved on, vowing he would never be so stupid, or so trusting, again. Gage has said that he has been in many gangs and has witnessed each one destroy itself from stupidity, laziness, and chem usage, stating that he bolted before their end occurred.
Gage dislikes the Sole Survivor using chems or drinking hard alcohol. Most likely due to seeing many raider gangs destroyed because of their addiction.
He says and believes that the raider "gangs" in the Commonwealth are stupid.
Gage is currently the only Fallout 4 companion who will sell to the Sole Survivor, however this is limited as he will only sell in Nuka-Town.
Gage will not enter the Prydwen's cockpit during Elder Maxson's speech. This refusal is also shared with Strong.
Gage's default weapon and armor are superior to that of most companions, allowing him to be effective in combat with minimal investment.
If Gage is carrying any items for the Sole Survivor when they choose to look at the wares he has for sale, he'll offer them up for sale in addition to his normal inventory. Be careful to avoid buying them by accident.
Attacking any of the Nuka-World raiders and turning them against you will also cause Gage to be removed as a companion and begin attacking you.
One of his lines of dialogue refers to mirelurks as "mudcrabs", a creature from Bethesda's The Elder Scrolls series.
Gage is annoyed by mole rats, often stating after battling them: "Mole rats... another pain in the ass the Commonwealth insists on shitting out".
In addition to mole rats, Gage also states his contempt for insect and arthropod based creatures by saying: "Boss, you ever ask yourself why the hell these things got so damn big? As if they weren't already disgusting to begin with."
Despite having an eyepatch, if one gives him eyewear then removes it, there's nothing wrong with his eye, due to engine limitations.
There is no way of putting the eyepatch back in place after giving him another eyewear.
If you engage in dialog with him at certain angles, you can see his eye under the eyepatch.
He does not think highly of any main storyline faction:
He sees the Institute as a bunch of scientists playing God, with the Commonwealth as their world and its people as their lab rats.
He thinks lowly of the Railroad, believing them to be furthering the Institute's gains by transporting their creations away from the Commonwealth.
He does not hold the Brotherhood of Steel in high regard. In fact, on several occasions he refers to them as another gang of raiders, just with a sense of "legitimacy."
And finally, he sees the Minutemen as a nuisance, though when one agrees to lead the Minutemen, he reluctantly states that "there's not really a better option."
Like MacCready and Old Longfellow, Gage's teeth are rotted.
Unlike other companions, if you select "Best Friends" or "Thank you" during his max affinity speech check, Gage will not offer another opportunity to select "Romance" at a later date.
pcps4xboxone If you enter combat during Gage's final affinity conversation, you will not unlock the perk Lessons in Blood and will not be able to re-initiate the conversation without reloading a previous save. [verification overdue]
On PC, with affinity over 1000, you can fix it using the console commandsetstage DLC04COMGage 220 with Gage selected.
xboxone When entering Nuka-Galaxy, Gage might fall off a platform resulting in him being downed. No stimpack option is available, and normal dialog is all he offers. [verification overdue]