Unpacking the Fighter

With my handy new AnyDice function, I thought it would be fun to look at just how our Champion Fighter's growth looks. In 5e, the Champion gets a higher chance to crit and various stat boosts at different levels. I plotted how a typical greatsword-wielding Champion would fare against a chainmail-wearing (AC 16) enemy from level 1 to level 20 (yes, in 5e, you will encounter enemies with 16 AC even at high levels). I assumed he started with 17 STR, went to 19 at level 4, and went to 20 at level 6. Plots are of the chance he does at least X amount of damage in a round.

Here he is doing a normal attack:

And here he is with advantage:

Advantage is important for Champions. Not only does it boost the chance to hit, but it nearly doubles their chance to crit. With advantage, 1 in 5 attacks should be a critical hit at levels 3-15, and 1 in 3 from 15 onward. If you're playing a Champion, it would be wise to delay your attack until a fellow party member can flank.

Each set of clustered lines corresponds to getting an additional Extra Attack. What we can see is that, by far, EA is a bigger damage booster than any other improvement,  due to each EA having exactly the same modifiers. This is a big change from 3.x/Pathfinder, where each Extra Attack had a decreasing chance to hit, with the 4th generally being little more than ceremonial gesture.

From level 11-19, damage output grows fairly slowly. The curve stays in the same range, with odds of various damage levels increasing by no more than about 12% over the entire spectrum. Players shouldn't regard this a dead zone, however. Rather, this is where the Fighter becomes increasingly versatile and harder to kill. Indomitable helps compensate for what are doubtlessly unimpressive CHA, WIS, and INT scores, and he gets more stat boosts or feats than any other class. Of course, this is where D&D simply becomes more challenging. The most rapid relative growth is from levels 1 to 10, and from then on, parties need to get better and better at working together.