5e's Bounded Accuracy

One of the most controversial aspects of 5e (at least for die-hard fans of 3.x/PF/4e) is so-called "bounded accuracy." What this essentially means is there is very little built-in scaling of bonuses to d20 rolls, and player ability scores are all capped at 20. The +1/2 level bonus is now gone, and the magic item bonus is no longer built in. If you've played 3rd or 4th edition, you know that a high-level wizard can jump across chasms more easily than a low-level barbarian, and a high-level fighter can pick most mundane locks with ease.

What the whiners say:

It ruins everything! The whole concept of attaining godlike power as you level has always been a fundamental part of D&D, and now 5e has ruined it. Everything sucks now! This isn't D&D!

Actual D&D History:

A +1/2 level bonus is actually not fundamental to D&D.  This was actually new to 3rd edition. In AD&D 2nd, AC was based only on your armor, not your level. Each class' THAC0 increased at a different rate, so no, the Wizard never got any better than useless at trying to stab someone in full plate with a tower shield. Only the thief had any ability to disarm traps, sneak, or pick locks at all. The fighter eventually got better AC not by leveling up, but by first earning enough money to buy plate mail, then eventually finding some cool enchanted gear.

The concept:

The designers of 3rd edition brought in this entirely new idea that as players gain experience, they should just naturally become good at things. A wizard should, after surviving enough scrapes, eventually be so handy with a blade that he could easily best a city guard in melee combat, pick the lock on a house, scale a rocky wall, and bluff his way into an orc stronghold. 5e is a return to the old AD&D concept that fighters are good at fighting, thieves are good at thieving and wizards had best stay a healthy distance away from hobgoblins if all they're going to wear is pajamas.

How it worked in practice:

In actual practice, a 12th-level wizard's intrinsic +6 bonus to disarming traps didn't matter.  Any trap a DM threw at a 12th-level party was, surprise surprise, always a 6 difficulty points harder than anything he threw at them when they were first level. In practice, that big modifier on the sheet didn't mean anything. It was just a big number that felt cool to look at because it was so huge. But really, the novelty of rolling a d20+22 wears off pretty quickly when you realize everything you meet has minimum 32 AC. Players tended to complain that it felt like the world just leveled up with you. If you've never played AD&D, but you've played The Elder Scrolls: Oblivion, that's what I'm talking about.

The math:

Without getting into details, a 5e fighter will usually have +5 to hit, 1 attack, and 18 AC at level 1. At level 20, he'll have +11 to hit, four attacks, and at least 20 AC. The wizard will probably never have better than 10 AC and 1 attack, and his bonus will go from +2 to only +6. The "feel" is much more like AD&D than 3.x/PF/4e.

How it works in practice:

I find I can throw greater variety into dungeons and still have it be fun. 4e's "minion" monsters are no longer necessary. Low-level monsters serve as minions just fine now. The main thing is that as players level up, the game feels less and less "flat." By level 20, the barbarian becomes a fire hose of damage, but he's *more* vulnerable to a mind-control spell cast by a monster of his same level than he was at level 1. The wizard unleashes insanely powerful blasts of magic, but an ancient dragon will make mincemeat of him if he gets too close. The challenge of the game actually increases as the party levels up, because the players have to become more skilled at exploiting their strengths and avoiding their weaknesses.