You won't get far standing around punching radroaches all day. Follow this advice to work the XP system and level up quickly.
Fallout 4 is an RPG at heart, which means your character and progression through the game is tied to experience points. All major actions earn you XP; killing enemies, unlocking doors, discovering new locations, crafting gear, helping out with side missions and of course completing the main quests.
To get the most XP you need to work the system a little to maximise your rewards. Get into the right mindset: unlock every suitcase and safe - even if there's nothing handy inside you get the XP for the action.
Now apply that same mentality to the way you approach the game.
Early game, play the Idiot Savant
The Idiot Savant Perk is great for early levelling. It's a Luck Perk that awards you 3x and 5x XP for any actions. As this is a Luck Perk it's random as to whether you receive it or not. While it's not crucial for small actions that reward XP such as killing average enemies and picking locks, when it comes to the XP awarded for completing quests, you should always Quick Save just before reporting your completion to the quest giver.
Once you've Quick Saved, approach the quest giver to complete the quest. If you're not awarded the 3x or 5x bonus, just reload the game and repeat the process until you do. With this Perk it's also worth noting that the lower your Intelligence is, the more chance you have of receiving the XP bonus. It really pays to act dumb.
What you should also be doing is saving up those Skill Points awarded for every level you unlock. Consider if you really need that new Perk, or whether you want to save them to boost Intelligence later on. Because you can't be an idiot all your life.
The downside here is that without a decent Intelligence stat you'll miss out on Perks such as Gun Nut, Hacker and Science. That's fine so long as you know this will be a weaker area for you. You can compensate in some areas by using the right companion - Valentine will do hacking on your behalf, for example.
Farming side quests
There are a bunch of side quests that are ongoing and repeat whenever you accept them. If you join the Brotherhood of Steel early on you can accept quests from Scribe Haylen and Knight Rhys. One sends you to new locations to kill, the other to scout, and these overlap. These quests are easy, and you'll be rewarded with XP for kills, finding new locations and completing the tasks. The same can be said for Preston's Minute Men quests. Set aside a couple of hours and string them together one after another and you'll fly up a fair few levels.
Mid to late game, it's all in the Intelligence stat
It's not immediately obvious, but the more intelligent your character, the more XP you will earn. So it makes sense to unlock Intelligence ranks once you're done milking the Idiot Savant stat.
It's not an exciting way to start the game - we all want some of the cooler Perks - but the reality is they'll come sooner if you boost your base Intelligence stat. You get a bonus XP multiplier for each Intelligence rank you unlock, a percentage-based bonus on top of whatever XP you normally earn.
The more Intelligent you are, the more XP you're awarded. It's a virtuous circle. When you're completing big quests at higher levels you'll be rewarded with much more XP - this is why you should save up 5 or more Skill Points and jump your Intelligence up in one go.
Farming The Learning Curve quest
Once you join the Brotherhood of Steel and progress to a certain point in the game (SPOILER: killing Kellogg), you'll be called upon by Brother Danse. Go with him to the Prydwen where you'll be introduced to all the Brotherhood members.
It's here you'll meet Proctor Quinlan on the main deck. Agree to help him and he'll ask you to do the Learning Curve quest, which you can farm repeatedly like so:
- Equip a long-range, high-powered sniper rifle with a scope.
- You're asked to protect an ally of the Brotherhood. Sod that, you're going to kill this person instead. Repeatedly.
- Once the quest is active, head outside to the outer walkways and go to the far end so you're as far as possible from the Brotherhood Knight on patrol near the door. If he sees what you're up to he will kill you.
- Crouch to reduce visibility (or use a Stealth Boy), and shoot the target you're meant to be protecting in the head. He or she will be down in Boston Airport below you.
- When the quest objective changes, go and see Proctor Quinlan and tell him the target didn't make it.
- Quinlan will still award you between 300 and 400 XP depending on your Perks (and Intelligence, remember!). You can now agree to help on patrol again and repeat the whole process. Do this in an hour and you'll earn thousands of XP