Eyeballing a super-simple RPG

[J-H]

This would be for my 3 and 5 year old, so I am keeping everything super simple. Everything's on a D6.

Character Class
Knight:
9 hit points
4 armor
To-hit +1
Damage 3

Talent (pick any 2)
Anything outside of combat is resolved on a D6 roll, 4 or higher succeeds. A Talent grants Advantage on this roll.
Climbing
Healing (2hp)
Knowing
Spotting
Sneaking

Actions:
Each character gets 2 actions per turn.
Attack: Make an attack. Roll 1d6+to-hit versus target's armor. Deal damage if you hit.
Defend: Dodge and raise your shield. Increase your armor by 1. Stacks with itself if used twice.
Move: Move a ways towards an enemy or away.

Enemies
T-Rex
15 hit points
3 armor
Damage 4
To-hit +2
Special: One attack per turn. May make a scary roar at someone, causing Disadvantage on their next attack roll.

Poisonous Snake
2 hit points
1 armor
To-hit +1
Damage 2, plus lose one action next turn
Special: 1 action per turn instead of 2

Wolf
5 hit points
2 armor (agile)
To-hit +1
Damage 2

Evil Knight
9 hit points
4 armor
To-hit +1
Damage 3

Thief
7 hit points
2 armor
To-hit +2
Damage 2

Anything broken?

[Ventruenox]

I'm assuming enemies only get one action each per turn?

Looks pretty straightforward. You may also want to take a look at Monte Cook Game's No Thank You, Evil.

[MoiMagnus]

While the complexity looks right, I fear for the readability (too many additions).

Rather than having those numbers, I'd probably craft for each enemy a sheet with:
+ a drawing of the list of faces of the d6 you needs to hit the enemy
+ a drawing of the list of faces of the d6 the enemy needs to hit you
+ as many "swords" drawn as the number of damages it does when attacking
+ an image of the enemy (facultative)
And I'd use tokens for hit points, because "getting rid of as many tokens as the number of swords" is something much easier than a subtraction

And if you have some other tokens to put on top of the d6 faces of the enemy sheet that are "cancelled" when an enemy attack one of your kids that had dodged, so that it become very material that "dodging make this face not work", it will probably be good too.

I'd also want to use some small piece of paper for every additional information (the two Talents, the disadvantage given by the T-Rex, ...), so that everything is represented by something material gain or lost.
(That's a very basic concept of game design: prefer visual information to abstract information for everything simple enough.)

[J-H]

I test-drove this during dinner, so I had all the paperwork.
No tokens - I want the 5 year old practicing his math to see what hits and what doesn't.

So far so good, they beat 2 poisonous snakes, 4 wolves, and (barely) a T-Rex before sneaking away (both took Sneak) finding a cave (Knowing) and then (Climbing) into it.
3 year old's attention span isn't so great.

I let them each pick one thing to be better at, which was a +1 to one of their 4 stats (or +2 for hp).

[Grod_The_Giant]

I worked on something similar a while back. The idea was that the whole thing would fit on one notecard, using Fate Accelerated style Approaches instead of D&D stats and Apocalypse World style Moves for combat.