Flappy flap

Lately I have been playing some DnD with a couple of people using an alternate race that grants flight.  They are a type of Tiefling, decended from both human and infernal creatures, and their bat-like wings allow them to fly around.  They do lose out on standard Tiefling abilities to get flight, but as anyone who has ever tried to GM a game with a flying character in it can tell you, flight is busted and is vastly superior to other racial abilities.

The counter argument is usually that at level 5 a Wizard can cast Fly.  That holds no water though because this costs a memorization slot, one of your few high level spells for the day, only lasts a short time, and can cause you to fall to your death if you fail a Concentration roll.  It also doesn't address the issue that flying destroys a huge percentage of encounters and challenges that characters deal with from levels 1-4.

We definitely found flying to be a serious balance issue in our games so far.  I certainly think it needs adjustment but which adjustment exactly is tricky.  A lot of GMs just flat out ban flying races, and I think that is a fine solution.  You could build a race that flew but was packaged with hideous restrictions to go along with it, but honestly I don't think that would be much fun.  The problem is that flying destroys so many basic assumptions about the challenges in the game that you can't just fix it by making the character otherwise useless.  It would still end up that the flying character automatically defeats whole swaths of the game by themselves, and then does nothing otherwise.  Hardly interesting.

Our flying characters were able to avoid traps effortlessly, hover in the air using ranged attacks to trivialize enemies, and evade spell effects.  This sort of thing can be solved by making a set of rules about how flying works that are restrictive in reasonable ways.  For example, characters with flying want to be able to hover in place, fly straight up, swap direction instantly, and perform tasks without any hindrance.  None of that needs to be true, and in fact it seems kind of absurd when you consider what flight looks like on a large bird.

A hummingbird can do all that stuff, but hummingbirds are tiny and eat stupendous amounts of food to accomplish their feats of aerial magic.  A flying character is going to look a lot more like an oversized pelican weighed down by a ton of gear.  No hovering for them!

I imagine the following rules for flying characters.

1.  You can only ascend at 1/3 of your flying speed.  

2.  While aloft, you must take a move each round for your full flying speed or fall.  

3.  You need at least a 20 foot wide space to turn in.

4.  All attacks made while flying are at disadvantage, and all spell casts require a Concentration check or the action is wasted and the spell is lost.

5.  You can carry at most 5*Str pounds of gear while flying.

This makes you feel not like an attack helicopter or a hummingbird, but rather a big clunky flappy bird that can get aloft if you need to.  You can still get up to the tower to grab the thingie when your companions would have to climb.  You can scout effectively and avoid many outdoor hazards.  You can even engage melee opponents from on high, though the penalty to attacks and spells makes this much less effective.  These are significant advantages.

What you can't do is constantly be out of reach so your friends have to soak all the attacks.  You can't just zoom around ignoring all area control type spells.  You can't launch yourself through tiny dungeon corridors, attacking enemies at will then dodging out of reach again.  

This ruleset means that outdoors, outside of combat, flying has huge advantages.  This feels right!  It should be great in that situation.  In a fight though being a bipedal creature with big clunky wings just isn't an advantage unless your opponents are totally unable to attack someone in the air.  In the tight corridors of a dungeon wings aren't much use at all, except perhaps for gliding over a pit of spikes.

That feels, to me at least, like a good spot.  I would still love to have flying, and I think it would still be the absolute best racial ability, but it won't break most combat encounters and it will be situational.

When I built Heroes By Trade I included a race with wings, but their wings weren't strong enough for flight.  They could slow their fall easily and thus jump down from any height, and even run on water for short distances using their wings to help out.  Players found this useful and thematic, but it never broke anything.  That might be my best answer yet if someone really wants wings, though I suspect that most people that want wings really do want to take off into the wild blue yonder.