I was running a D&D kids camp and the kids were struggling when it came time to level their characters. I took the time to scour the internet, D&D books and my own notes to come up with the following information to give them as a handout. I hope it helps others.

Leveling your D&D Character, Step by Step

Step 1: Increase Your Maximum Health and Hit Die

Each time you gain a level, you gain 1 additional Hit Die. Roll that Hit Die, add your Constitution modifier to the roll, and add the total to your hit point maximum.  If at any point your Constitution modifier increases, your hit point maximum increases too – by one point for each level you’ve gained.

1. Roll your hit die
2. Add your constitution modifier
3. Add that total to your Hit Point Maximum

Step 2:  Check for Ability Score Improvement.

You typically unlock the opportunity to improve your ability scores at levels four, eight, 12, 16, and 19.  Some classes, like Rogue and Fighter, grant ability score increases at different levels.  When improving your ability scores, you can choose to increase one ability by two points or two abilities by one point each – though no ability score can go over 20.  Alternatively, you could choose to take one of the D&D 5E feats instead (this is on a separate handout).  As your ability scores increase, so do their individual modifiers.

1. Increase ability/abilities score(s)
2. Adjust modifiers
   1. Skills
   1. Attacks
   1. Save DCs
   1. Initiative
   1. Spell Save
   1. Passive Perception
   1. Spell Attacks
   1. Damage Bonuses
   1. Armor Class
   1. Movement (not all classes)

Step 3:  Check for Proficiency Improvement.

Your proficiency bonus is a modifier added when your character uses certain skills, tools, or items. It doesn’t always increase when you level up, but it has a big impact when it does.  You can expect your proficiency bonus to increase at levels five, nine, 13, and 17.

Step 4:  Check for new Class Abilities.

Check what class features you get at level up. Now, you won’t always get something (a lot of spellcasters don’t get a ton of them). But, it’s integral to your class’s progression to add a new feature any time you get one.

1. Check the chart for your class.
2. As you go up in level, if a value goes up on the table, use the new value.  (The plusses are not cumulative.)
3. If you have a proficiency bonus increase, make sure to increase all the places on your character sheet (like trained skill checks) which depend on that proficiency.
4. Check the features column.  Some features have per-level scaling not mentioned in the chart.

Step 5:  Check for new Race Abilities.

Some racial traits get better.

This is also just something you’ll need to look out for. Usually, it’s when you have the ability to cast spells — you may get more at higher levels. In other cases, damage increases.

In the Player’s Handbook, this only applies to the Drow Elf subrace (spells), Dragonborn (breath attack), and Tieflings (spells). Oh, and Hill Dwarf gets an additional hit point per level.

Step 6:  Add any new Spells to your Spell List.

Every spellcasting class learns new spells at different rates. Now, some may be similar, but you should check when your specific class gets them. You don’t want to forget grabbing new spells whenever possible.  Also, check to see if you can switch out spells.

Switching out spells can get a little complicated. It is recommended you consider which spells were helpful during your adventures and which ones you never used. Because now’s the time to make an exchange.

Damage from most attack cantrips goes up at certain points.

These are “level 0” spells — they don’t use spell slots or preparation and if known can be cast at will. Most damaging cantrips increase in power at 5th, 11th, and 17th character level. This is noted in the spell description, not on the class chart, because it scales with character level not class level (which may differ if you multiclass — see below). If you have cantrips written on your character sheet as attacks, this is good to be aware of when you level up.

It’s also important to realize that other spells don’t do this. Some spells note that they can be cast using a higher-level spell slot and give what the effect of casting in that way would be. For example, Magic Missile says:

At Higher Levels. When you cast this spell using a spell slot of 2nd level or higher, the spell creates one more dart for each slot level above 1st.

It’d be easy to interpret this as meaning “2nd character level”, but D&D uses “level” to refer to different things (in 5E, character level, class level, and spell level are all distinct). Here it refers to spell level — Magic Missile is a first-level spell, but if you cast it using a higher-level slot, you can create more darts. From the class chart, you can see that wizards gain 2nd-level spell slots at 3rd class level. A 3rd-level wizard has two 2nd-level slots and four 1st-level slots, and so could cast magic missile six times, with two of those times gaining an extra dart.

In general, except for cantrips, spell damage (or number of targets, etc.) does not increase as you level up. Instead, you gain higher-level slots, which you can use to cast some spells with greater effect.