Hello all. So as the title suggests, I will be DM'ing for the first time for a party of two brand new players. I only have a few sessions under my belt as an actual player but I've been consuming D&D for several years in the form of podcasts and YouTube campaign sessions. I have read and collected many books, both from official WotC and from other sources. I know that 4-6 players is typically the sweet spot. However, I really want to prepare a fantastic cooperative storytelling experience for my friends and we just don't have other players in the rural area that we live. 

So I have a few ideas floating around:

1. Tone down encounters a little to help with combat. Ie: lower enemy health, a -2 bonus to saving throws and damage rolls from the enemies, etc. Whatever handicaps I feel could help make the encounters challenging and fun but not outright insane.

2. Have them employ a companion/mercenary/bodyguard. I will be running Dragon Heist for our first campaign and have thought about Volothamp giving the characters a control rod to a construct bodyguard in his possession (a Warforged fighter with very low intelligence) and not have him make any skill checks or game decisions without being asked to do so by the party. If I go this route Volo will give them the control rod in luei of the 10gp a piece when they leave to find his missing friend. I like the idea of making a possible story arch for the construct in which the party helps to "awaken" it if they so choose, effectively giving it sentience and freedom of choice.

3. Since this is everyone's first game, mine as a DM and theirs as players, I floated the idea of a homebrewed "save game" feature. Only to be used for TPK's. Upon TPK'ing, the party could "reload" and "lower the difficulty." Or try again at the same difficulty. This, of course, may seem like sacrilege to many veteran D&D players out there but my main goal is to ensure that we all have fun above all.

Does anyone else have any ideas or thoughts related to running a campaign for small parties or about the ideas I mentioned above? I'd really appreciate some input.

Edit: I let my players choose the classes and races they wanted to play for roleplaying purposes. I didn't want to limit them to what might be the most effective duo. That said we are working with a Wizard and a Bard, which is why I may strongly suggest but not force the use of the construct bodyguard.

Welcome to the other side of the screen!

As a consumer of live play events, my first suggestion is to temper your expectations of your game to you and your friends' abilities. Roleplay does not have to mean character portrayal. If you and your players get into that style of game, then by all means forge ahead in your own manner. I'm merely suggesting that it not be a requirement. I digress... on to your ideas!

1) As has been mentioned, combat is hinged on action economy and dice rolls. We can't alter dice rolls, so we work with action economy. I've run small party games and would encourage using the Sidekick rules fromTCoE or the UA version found here. As far as toning down the individual monsters, there are some good DM tactics by SlyFlourish regarding what he calls Dials of Monster Difficulty. These can allow you to tailor the encounter difficulty on the fly. I would recommed using these effects sparingly and judiciously to avoid killing off a monster that would potentially have downed a PC. (Effectively giving the PC plot armor)

2) The idea of using mercenaries and NPCs to bolster party strength can work in the near term. I try to avoid using NPCs in the party for longer than the current quest/mission and stick the NPCs into the role of guide or advisor. If the plan here is to increase party numbers, I'll refer back to Sidekick Rules. Giving the party a Patron to provide them with quests and plot hooks can lessen the burden of decison on the party. It allows the party to in-game admit they don't know where to go next and ask the DM what to do. 

3) The threat of losing the character that you have a vested interest in is what makes PC death dramatic and important. Taking that away can remove the fear and tension from your game. While some people don't enjoy those emotions, the release of those emotions when the PC is victorious at the end of a significant challenge is always enjoyable. That said, I don't dislike this idea, but would suggest using it sparingly. You could wrap it in the narrative guise of a premonition or a dream sequence. Maybe something like Groundhog Day. Again, this feels a lot like plot armor, but I understand the premise of not wanting to TPK the new band right out the front door of the Inn.

• Running a fairly large adventure like WD:DH can be a challenge for experienced DMs. I will deferr to your confidence in your abilities. I would have maybe chosen LMoP or some small homebrew adventure that would ease both you and the players into learning the game over some time. This would also give you the opportunity to learn and practice being behind the screen. 
• Try to keep the players in the mindset of telling you what they want to do, not what skill do they want to use. This keeps them in the focus of attempting and describing action and allows you to focus on adjudicating how that action resolves.
• In the same vein, DMs call for rolls, not players. There will be times that you decide that a roll is not necessary and that the PC just fails, or succeeds depending on the rules of your world.
• Avoid making a simulation of the real world in your game. That's not why we play games about elves and make-belive dragons. 
• Don't be discouraged or worried if (more like when) your players run the adventure outside what the book outlines.  No plan ever survives first contact with the PCs. 
• Have fun! The DMs primary focus is to run a fun game. Not a strictly rules-as-written simulation of the real world. The point here is for the DM to make rulings, not to adhere specifically to the rules. The rules don't run the game, the DM does. Rules give us the method of adjudication for our game, thus they are ambiguous by design. 

Good Luck!

I've been running 2 player D&D for a while now and contrary to most advice I have run adventures with a DM PC NPC - and it's been quite fun, Think it might have improved my role play in fact having a character who's developing alongside the players and has frequent interactions with the PC's. Ofcourse one has to be mindful that the DM PC NPC is not stealing the limelight but it can make for fun role play to have a voice in the party...
Balance wise getting your players to hire some shady NPC hireling is probably quite fun but adjusting encounters is going to be something you'll always end up doing for one reason or another... I've found Sly Flourish's articles invaluable, I think you might find this one quite relevant - The Dials of Monster Difficulty        

Edit: Kaavel,

I hadn't thought much of action economy before so I appreciate you and BigLizard for bringing it up. I will have to do a little more research on that part.

I have TCoE and I'm now in the process of looking into sidekicks.  Thanks for that point.

I also didn't really think about players saying what they want to do rather than calling their own skill checks but that seems much more in line to the live play shows I've watched/listened to so I will go with your recommendations there. 

Overall you have all made lots of great points. Thank you for taking the time to help me out.

Justin Darkness, I appreciate that you and Kaavel have pointed out SlyFlourish's material. I have his Return of the Lazy DM book and have been reading through some of his blog posts about this particular published adventure. I'll definitely be reading up on his Dials of Monster Difficulty now. Mich appreciated.

I think the notion of a "save" feature isn't bad, and can be integrated if you set the pace that they take a long rest shortly before an encounter you are unsure of.  If they fail they fade to darkness, then awaken, in their camp, having shared a nightmare.  You can then RE-introduce them to the encounter, with adjustments, based on where it went to crap lol, allowing them a better chance of survival.

I, too have integrated DM controlled NPC's, and they have ZERO input to ideas, plans and so forth, BUT are able to utilize skills if the party directly asks them.  You could slip in a suggestion or idea, if they seem to be truly stuck, but again, the NPC's I assign my party tend to be kind of a tool they have and must state that they wish to use the tool when applicable.  The Bard, for example, stood idly by, with proficiency in his Thieves' Tools, while the party tried to smash in a door.  When they failed, one of the party stated it would be nice if someone could pick a lock, where the Bard then offered to attempt it.  He was there, he had the skill but didn't immediately jump in to take the spotlight (and if they hadn't rolled absolute crap, breaking it down would have worked)

There are a few options for small parties.

1) NPCs or sidekicks that join the party but try to avoid having them steal the spotlight. If the NPC fighter is doing all the work and the NPC cleric all the healing then the bard and wizard might not be doing much.

2) Have each player run 2 characters. Popular in some circles, it does make role playing a bit more effort but does mean the players are invested in the actions and survival of both their characters. It also gives you a party of 4 and lets the players (especially new ones) try out different mechanical options at the same time. The downside is that it is more to learn.

3) I would not usually adjust monster saving throws or AC most of the time - usually just their hit points and the number of opponents encountered at once, along with the tactics that they use. Most of the time, that is sufficient to keep things interesting and balanced. However, keep in mind that level 1 is fragile and a critical hit can easily knock out or even instantly kill a PC depending on the creature involved (e.g. 1 orc). I ran a test combat with my daughter just to see how it worked with one orc vs two level 1 PCs - a ranger and something else. It almost turned into a TPK when the orc landed a critical hit and took out one of the PCs while both PCs rolled low and missed the first round. So low level can be swingy and dice dependent so advancing the characters to level 2 after one session or at most two would be my suggestion.

First time dm also running a party of two noobs here. The following are a couple mechanical tricks i employed as DM that kept my party alive-

1. At low levels I rarely added the damage bonus from a monsters attack (ie if the damage is 1d8+2 the player only suffers the damage from 1d8), this mild handicap allowed them to suffer some consequences whilst keeping them alive long enough to learn from their mistakes.

2. I think its already been mentioned but lowering the AC and HP of monsters is totally fine. I lower the corresponding XP as well to compensate. I felt like it was more important that my players fought monsters that were in line with the story or location than just endlessly throwing twig blights at them out of an abundance of caution.

3. Again, at the lower levels, NEVER let them fight something that could one shot them with a crit. If they lose almost all their HP from one blow at least they've got a chance to run.

4. Speaking of running, if they are new to the game i would be sure to go over the actions besides attack that i think new players don't utilize- Dodge, Ready Action, Disengage, etc. Using these in key moments can really help.

5. A helpful NPC is great but can make your job, or the players if they have to run it, more complicated. I employ them occasionally now but I found having some magic items early on to aid them worked out fine. My warlock was given a ring by a wizard who knew her mentor that basically casts Mage Armor if she suffers damage. It needs a day to recharge so it isn't too OP but i think it worked pretty well as a set of training wheels.

I was very nervous at our first game but a few months in I find myself feeling extremely comfortable. You'll learn how to effectively challenge a small party once you learn their habits, approach, and combat style. And if they're new to the game they'll have no idea if you're bending some rules for their benefit. Good Luck!