While 5E is far simpler than the "rules heavy" 4E and 3.5E versions of D&D, it is still very much a "rules medium" game - if not "medium plus" - and probably requires a base level of either nerdy 12 year olds, or non-nerdy 14-15 year olds to grasp the entire RAW.
I was thinking of introducing my two non-nerdy (but imaginative) daughters, age 13 and 10 to the game, but wanted to trim it down a bit. My 13-year old is quite young for her age with limited mathematical and analytical skills, so think more in terms of my younger daughter as a baseline.
I think over time they could grasp the full rules, but I would rather start simpler.
Preliminary thoughts:
*Get rid of skills, use ability checks only. This is pretty obvious, even a no-brainer. PCs would be proficient in whatever their class saving throws are, with a few exceptions (e.g. rangers would have to get a hybrid Nature/Survival skill).
*Get rid of backgrounds, archetypes, sub-classes. Sounds like a lot, but could do without, at least the first go around.
*Trim class features. Not sure exactly how to do this, as they are so central to what differentiates classes. But one of the main complexities of 5E--as with prior editions--is keeping track of the many contextual modifiers. For example, I'm currently playing a ranger in a ToA campaign and am always forgetting to cast Hunter's Mark or remember to use the Colossal Slayer feature for the Hunter Conclave - and even more so the Dread Ambusher feature for the Gloom Walker Archetype.
*Fewer class options? Maybe no sorcerers, for instance, with their metamagic. I could let warlocks and monks go. Maybe the rest are fine.
So essentially I'm talking about a stripped down version of the game, focused on race, class, and ability scores, with maybe trimmed class features. I'd have to adjust what classes can do as the stripping down of features and sub-classes would hurt non-spellcasting classes more than, say, wizards, who main thing is their spells.
I could run the monsters and DM stuff more RAW, although with a very liberal fiat approach.
Thoughts? I could also just run them through something like Wrath of Ashardalon, but wanted to give them the "real" D&D experience of theater of mind immersion rather than a boardgame. As much as we enjoy boardgames (logged many hours of Dungeon, although recently our go-to has been the tried and true Monopoly), they just aren't the same as D&D.
I've been there, and my children were several years younger than your when we started playing 5e, so here's what I have done for them:
1-
pregenerated characters: have the characters completely designed and the character sheets printed out, so that you can start playing immediately; have 1-2 more characters than players ready, and let them choose which one to play; leave only the name, gender, race (see next) and narrative details (including physical description, personality, backstory...) open for the children to define, but also tell them they don't need to choose everything immediately
2-
use human stats: let them choose a race only for narrative purposes, but keep the human stats so that your pregenerated characters are ready to use without modifications
3-
iconic characters: if it is their FIRST time playing D&D, do them a favour and start from tradition: pregenerate Fighter, Cleric (Life or Light), Rogue and Wizard characters; suggest Human, Elf, Dwarf and Hobbit (yes use the forbidden name); allow something different only if your children ask (one of mine wanted to play a Druid and I knew it before so I also pregenerated it; another choose to be a Centaur, do not worry about weird choices, just sometimes go with the narrative of it)
4-
choose low-complexity options: sword&board Fighter with Defense fighting style, simplest spells as possible for the casters, minimal equipment, and generally favor passive abilities over activated ones and at-wills over resource-based ones (although these won't really come up at 1st level -> because OF COURSE you shall start at 1st level!); use a fixed ability score array that focuses on what is iconic for the class, and with no negative bonuses, the easiest is probably to have 2-3 positive bonuses and all others zero
5-
do not explain the character sheet: it is inevitable that your children will ask what are all those numbers, you can spare some words but don't go through it top to bottom; tell them you will let them know when they need to use those numbers; I used my own simplified character sheet (
http://www.enworld.org/forum/rpgdownloads.php?do=download&downloadid=1415) but note that this encourages some simple math calculations on the fly at the expense of not having everything ready on it
6-
do not explain the rules: again, tell your children that the rules will be explained only when you need to use them
7-
hide non-prepared spells: this is a small but helpful thing, at first write on the character sheets only
prepared spells and not all
known spells, which are particularly too many for Clerics and Druids; have the simplest or most iconic prepared; wait until later to reveal they can change their daily selection
8-
introduce combat encounters gradually: I started with a couple of very easy and short combats in ToTM mode, 1 big stupid monster so that there isn't much tactics to think about, and told them only the BASIC combat actions first i.e. Attack/Cast/Use a Potion; then at each new encounter I added some novelty: multiple monsters (introduce minis), monsters with ranged attacks, cover, darkness, spellcasting foes, monsters with immunities, etc...; there is absolutely no need to dumb down the rules, just don't use all the options at once
9-
protect them from accidental death: it won't happen easily, but if according to the rules one of their PC should die, tell them instead "this is when something bad happens", and let them choose together what is "bad": are they knocked out unconscious, injured for a while, captured, lost, equipment broken?
10-
play simple straightforward adventures: make it clear they are the good people against the bad ones, give them simple choices and always a recovery chance should they still make a mistake
