Don't Repeat It Twice Challenge (Fallout 4)
The main objective is answering the question: "How many levels could possibly be gained for beating 100% of Fallout 4, without relying on XP grinding, RNG, and uncertainty?"
This is not a super pure speedrun-grade challenge, because what is grinding and what isn't can be endlessly debated about. The key words are approximate and estimation. In my take on this, I decided to exclude:
- settlement usage, except for the absolute minimum needed for quest objectives, and things like putting a bed and a couple chests for yourself
- save scumming or manipulation of any kind, especially involving Idiot Savant and legendary items
- doing any radiant quest more than once, except for the minimum needed in quests
- repetitive fighting in random encounters with the same enemies, unless unavoidable
- buying components solely for XP gain from crafting
- cooking the meat from your kills for XP gain, unless it's for your own consumption
- crafting items and automatrons from what you found in the wild.
The challenge is done in three runs to determine the approximate bracket of attainable level.
- first run: normal walkthrough without repetition and XP bonuses, with INT 1. (no bobblehead, even)
- second run: maxed INT, but without random Unyielding or Sharp items, only the guaranteed ones are allowed.
- third run: maxed INT, with spawning all 5 Unyielding armor pieces after level 5, to simulate extreme luck with legendary drops.
You can visit any place many times as long as you don't do it to gain XP repetitively. Some exceptions are debatable. In particular, you need to visit Slog and the Red Rocket in Quincy multiple times for respawnable tarberries and antifreeze, needed for Berry Mentats. You can do without it, but you'll be either relying on RNG for those items, or playing without that +5 INT bonus. The route is generally empty and you should avoid random combat points anyway, so there's no direct XP farming involved.
Crafting drugs and cooking the meat for your own usage is totally fine, as well as unique encounters on otherwise repeatable locations (such as Absalom).
XP exploits are OK as long as they don't stack with themselves or used to gain XP repetitively. For example, You're SPECIAL abuse for 11 Intelligence or the permanent squirrel stew glitch is fine, but infinite XP from repeating the same dialogue lines is not.
General considerations
Everything is done on a pure vanilla game, with no mods whatsoever. The exception is F4SE utility plugins like High FPS Physics Fix, Buffout, survival console unlockers etc, that don't change gameplay and don't break save compatibility. PLEASE NOTE: if you use Buffout, set EncounterZoneReset = false, as it fixes an important engine bug this plan will be relying on. Survival difficulty is the best to get more XP from kills, and to avoid respawnable enemies since the respawn timer is a lot longer on survival.
Starting SPECIAL: INT 10 is obligatory, PER at least 6 to get the Night Person perk immediately.
Playstyle is not very important, but VATS seems most logical since you'll be playing a very squishy character and it provides plenty of protection. Drug use is a must because Berry Mentats provide a large INT boost. Since you probably don't want to grind the components for them too much, you can max Chemist and install BioCommMesh into your chest armor - after that, you'll be spending just one BM per your active period, i.e. one a day.
Your daily cycle should be like that: sleep till 6:00PM go get Night Person bonus. Do quests and kill enemies until 6:00AM. Then trade if you need to, and sleep again till 6:00PM. Always sleep at least 7 hours to get Well Rested bonus (+10%) or Lover's Embrace (+15%).
Perks to choose: Night Person is obligatory. The desirable ones are Chemist and Aquaboy/Rad Resistant, because you'll be relying on Unyielding a lot and will want to control your rads. Also Hacker and Locksmith, for the challenge to be complete (although they provide a minuscule XP amount in the grand scheme of things, so you can ignore them as well, as I did).
Weapon of choice: Overseer's Guardian seems a no-brainer - it's obtained easily, is overpowered when used as an assault rifle in VATS, ammo is abundant. An alternative is .44 and Western Revolver later, they are somewhat weaker but weight less. Another good option is the extremely overpowered Cryolator fetched by Dogmeat or unlocked by Cait; the only way to obtain ammo in Commonwealth before level 15 is Cricket (another one is any dedicated weapons vendor in Nuka-World or Far Harbor). Keep in mind that cryo cells are extremely expensive, and maxing CHR is practically required.
Components for Berry Mentats to hoard:
- Tarberry. The only reliable source is the Slog, but traders sometimes have one or two so check them out when you can.
- Antifreeze. The most reliable source is the Red Rocket between Quincy and Quincy Quarries, where 3 bottles respawn each time the cell is unloaded. Traders also sell it, although rarely. Consult the wiki for additional locations.
- Mentats. Bought from traders and found randomly. Besides using them to cook Berry and Grape flavors, you can use them directly when you don't have Berry ones early on.
Optional useful items:
- Grape Mentats: Hubflower + Whiskey + Mentats. Whiskey is always in stock in DC (Wellingham, Bobrovs).
- Overdrive: Psycho + Nuka-Cola + Acid
- Psycho.
- Jet Fuel, makes you sprint for much longer: Jet + Flamer Fuel
- Refreshing beverage. Helps balancing below 750 for Unyielding by only curing 100 rads. Antiseptic (3) + Blood Pack + Purified Water (2) + Radaway (2) + Stimpak.
- Squirrel Stew. Gives +2% XP, but can be too much hassle for a bonus too small. It's Bloodleaf + Squirrel bits (sold in Diamond City) + Carrot (grows at the Slog) + Dirty Water + Tato (grows at Abernathy's and in DC). There's also a bug that makes the effect permanent, but I was unable to reproduce it.
- some frag grenades and mines probably won't hurt early on, to make storming the Boston Library easier.
Keep in mind that Psychobuff lasts longer than Psycho (8 minutes base vs. Psycho's 5), but anything that buffs END interferes with Unyielding, so you'll want to use normal Psycho once you get an Unyielding item.
Maximizing the Intelligence and XP gain
- Walk through the intro at INT 10. Don't forget to loot the lab coat in one of the dressers, that's a +2 INT boost.
- Go to your house in Sanctuary, ignoring Codsworth. Use a stimpak, lowering your base INT to 9. Take off your lab coat. Double check that you have 9 INT in your Pip-Boy. Read You're SPECIAL and choose Intelligence. Drink some water. You now have 11 base INT.
- Kill the boatflies in the next house, get the level 2, and choose Night Person as your first perk. Get to the basement and sleep till 6:00PM. From now on, you'll be playing only at night (6PM - 6AM) to boost your INT, except for trading in DC and other non-XP related activities. Your total INT should be 15 now. You should also play Well-Rested to get a 10% XP bonus for 12 hours (upgrades to Lover's Embrace later).
- If you prefer .44 as your primary weapon, collect it at the pump station by the lake nearby.
- Travel to Regi Blattaria's house (a ruined house west of Corvega plant). You want the ushanka hat that spawns here and gives additional +1 INT.
- Travel to Graygarden. There's a couple of ruined houses over the railway from it, and a bottle of antifreeze inside.
- Continue to the Arcjet plant and then to the Fiddler's Green Trailer Estates. You want a Live & Love issue #12, in one of the trailers, providing +25% XP from persuading women. Fighting ghouls is pointless now, just take the magazine and run away.
Depending on your variant of challenge, you may or may not want to travel to Sunshine Tidings co-op, and read the Wasteland Survival Guide #9 (double meat drop from animals). It provides a fair amount of XP later on (particularly in the Safari Adventure), but it can be considered repetitive XP abuse if you don't consume all that meat yourself. I skipped this in my run.
- If you want the Overseer's Guardian as your gun, make it to Vault 81. How you do it is unimportant, but consider the following:
- wandering too far away from the straight line will force more leveled enemies to spawn and lock to your low level;
- you probably want to collect enough chems/ammo/prewar money to barter for the gun and ammo;
- also probably some Grape Mentats to lower the price;
- maybe some junk for your first upgrade, so you don't reroll Myrna's inventory many times.
Regarding Grape Mentats: there's a guaranteed whiskey bottle is at the shack by the Wicked Shipping Fleet Lockup, and Wellingham and Bobrovs always have some in stock. Chem stations are at Sanctuary, Abernathy's Farm, Diamond City.
- If you have a .44, go buy some ammo from Eleanor (a trader between Fairline Hill Estates and Boston Police rationing site, not far from DC gate). She's your primary ammo source for some time, because nodoby sells .44s at low levels except her.
- Travel to Diamond City, upgrade your gun, resupply yourself, buy a house if you want etc, but most importantly recruit Piper. A hazmat suit from Fellon's Basement would also be useful later. If you're using VATS, don't forget to check wiki for AP cost of upgrades as well.
- Go to Goodneighbor, trying to avoid fights if possible. Enter Hotel Rexford and grab Live & Love issue #10, granting +5% XP with a companion.
- Travel to Bunker Hill, take the Live & Love issue #10 at the top of the monument, for +25% XP from persuading men.
- Head north and make it to the Slog, your main tarberry source. There are several respawnable tarberries regrowing at the pool each day, and Deirdre is selling some, restocking each 2 days. There are also some non-respawnable tarberries at the puddle by the road nearby, and also some across the lake; you can collect them once.
- Make some Berry Mentats. Travel to the Boston Library. Take the INT bobblehead in the back room, use your Mentats, fight the mutants. At this point, you should have 22 INT with Berry Mentats, or 17 without. By the way, there's an antifreeze bottle in the library and another one at the Red Rocket north of NH&M Freight Depot (you'll probably pass close to it on your way to the library, so why not take it).
- Head to the Vault 88. The most peaceful route, avoiding excessive low-level enemy spawns, seems to be:
- from the DC gate go north, cross the railway
- Eleanor's trailer
- go east, reach Relay Tower 0SC-527
- continue southeast down the hill slope, until the military checkpoint guarded by Mr. Gutsy
- turn east till the ruined highway
- walk north along the highway to the Quincy Quarries.
Take your Berry Mentats. Kill all raiders in the quarry. Hazmat suit is desirable but not required, you can easily walk in the radiation with Rad Resistant 2, almost not noticing it. Enter the Vault 88. Make your way to Overseer, talk to her, kill the ghouls, and build the terminal for her. Sit there yourself first, and get the permanent INT bonus. Now you should have 23 INT with mentats, or 18 without. This alone made me jump 5 levels up, from 12 to 17.
- Get out of the Vault 88, and look around for the Red Rocket near the quarry. There are 4 antifreeze bottles in it, 3 of which should respawn as soon as you leave the area (running to the University Point Pharmacy and back seems to be enough to regenerate them). That's your replenishable source of antifreeze, visit it again if you're short on it.
- Run back to DC, then to the Slog, and from there go to Nakano residence. Accept the quest from Kasumi's parents, and depart to Far Harbor.
- After the arrival and the initial dialogue, help defend the Hull. Report back to Avery. Meet Old Longfellow and let him lead you to Acadia.
- Talk to DiMA. Talk to Jule (sleepy synth on the 2nd floor) and exhaust her dialogue so she refuses to talk. Talk to Kasumi and complete her quest Where You Belong. Don't forget to grab the antifreeze bottle on a shelf somewhere around her. Talk to Faraday and accept his quest for the data storage retrieval. Talk to DiMA and accept his quest as well (Best Left Forgotten).
- Travel to the Nucleus. Talk to Richter at the entrance and agree to join Children of Atom. He'll send you to drink from the Spring, go and do it. Then follow the shadowy figure to the shack, kill the ghouls. Inside the shack, look for the password written on the footlocker. Unlock the figurine, take it, bring it back to Richter.
- Listen to the High Confessor's speech, follow him inside the Vessel. Talk to him, and offer your help to the family (Witch Hunt side quest). Don't forget to pick up an antifreeze bottle somewhere inside the sub. Finish the quest aggressively, accusing Sister Aubert of heresy. Recieve the Inquisitor's Cowl from High Confessor. Replace your ushanka with it. From now on, you should always have at least 400 rads on you. Your INT should be 26 with Berry Mentats, and 21 without.
- While you're still at Nucleus, enter the command center, following DiMA's quest. There are beds there so you can save and rest. Recover his memories from the terminal, solving the puzzle.
- Leave Nucleus and follow the quest Data Recovery. Travel to the boat, pick two storage drives up, touch the locked chest.
- Get back to Acadia. Give DiMA his memories, report to Faraday about storage drives. Mention the locked chest. Complete his quest.
- Sleep for two days, and Cog will initiate a conversation with you. Walk to Jule with him and speak with her. Speak to Cog again, and he will send you to investigate the boat again (The Price of Memory). Retrieve Victoria's Note at the locked chest located on the boat.
- Return to Acadia, and read the lab terminal on the lower level. Tell Jule truth about her past. She will give you a key to her footlocker and leave Acadia. Get your reward from the footlocker, located near the lowest level of the main staircase. It's an Unyielding synth chest armor piece. Replace your lab coat with it. From now on, you should have at least 750 rads on you. Your INT should be 27 with Berry Mentats, and 22 without.
- Leave the Island and head to the Nuka-World. Somewhere at this point, or a bit earlier/later depending on your particular case, you should hit level 25 - don't forget to take Night Person 2 immediately.
- After exiting Cola-Cars Arena, be sure to check the raiders you killed at the grate (if you killed any). They might have Fancy Suit & Tie on them, which gives +1 INT and allows armor to be worn over it. If you didn't found anything, speak to the clan leaders and then to Gage, making him a possible companion. After that, as long as he's your companion and you're in Nuka-World USA, he will trade with you. He should have some raider stuff in stock; you're looking for a Fancy Suit & Tie. If he doesn't have it, sleep for 2 days and check his inventory again.
- Max the relationship with Piper and Porter Gage this way or another, and romance one of them or both. Porter Gage should take the priority because of his perk (+5% XP for kills), but you're traveling with Piper for a long time and she's probably at 850+ affinity already, so finish with her first. Her bonus is twice the XP for persuasion and discovering new locations. Romancing a companion turns your Well Rested bonus from 10% XP to 15% for 12 hours, so you can clear some settlement, put a bed there and send your companion there; then use it as your base between nightly raids. Hangman's Alley is a good choice because it's close to Diamond City and is located approximately in the map center, more or less. I don't think putting a bed into a settlement counts as "repetitive XP abuse", and the impact on the challenge goals is insignificant.
With all of this done, INT and bonuses maxing is over. You should have 24 INT while sober now, or 29 INT under Berry Mentats. However, as you use Unyielding armor, you probably want to follow Automatron quest line and reach Fort Hagen Satellite Array in it. There's salvaged Assaultron head at the end of it, which irradiates the user, so it's useful to quickly gain some rads. Carry it at all times.
Proper quest order for maximum XP
Keep in mind that you need to complete Human Error (the Covenant quest) before Reunions and BoS arriving into Commonwealth. Siding with Honest Dan and Amelia yields the most XP as you have to kill everyone.