One of the more innovative conditions we kept from 4e was bloodied. It informs the DM and the players the status of the creatures, and gives a dramatic turn. I use that for roleplaying as well. If a character is bloodied, then the bloodthirsty monsters target them. If a monster is bloodied, then they might flee, surrender, or fight like a berserker. It's just good short-hand for predictive behaviors.
Many years ago I ran a D&D game for the kids, and I knew I'd had to adjust the game. I wanted to have heroic battles but not killing. Danger and fear were also prominent. But there were also a bunch of things I did differently because children were involved:
1. Everything talked - To focus on roleplaying every monster would talk. Seems silly but kids react very well to this. The giant spiders in the Dim Forest talked, just like in the Hobbit cartoon. Talking beasts is a common feature of fairytales, and works on many levels for a D&D game. For kids, it keeps them informed but without breaking character. So if I bit one of the PCs I'd say something like, "My poison will get you, and then you'll be my dinner!" Roll a save vs poison. The narrative is more important than the stats.
2. Only Monsters - I had no humanoids poised to fight them, only monsters. I converted The Return to the Keep on the Borderlands and swapped out every humanoid monster with a kind of Undead. All of the humanoids were NPCs who were either helpful or indifferent but could be reasoned with. The bandits in the keep were more like Robinhood rather than killers. They had no quarrel with the PCs or the keep, just the greedy merchants. They asked for help to take care of the Undead problem. I felt it was better to give the kids a sense that you can always talk with people, but not with Zombies.
3. Traps and Terrain - At least when I was a kid, we were always playing outside. Climbing trees, swings, monkeybars, and riding bikes, and pickup games of basketball or street football were common. Dangerous exploration is way more exciting for kids than it is for adults. Don't turn this into a dice rolling exercise. Let the narrative drive the rolls. The Caves of Chaos have a few decent traps, but I wanted something more exotic. Flesh eating fungal spores that turned Zombies into Skeletons changed the demographics of the Undead, and added another unusual layer of danger to the encounter. I put sections waist deep water to have Skeletons spring up and frighten them.
4. Make it Heroic - Skeletons are easy to destroy, and dangerous. It makes them feel more powerful when they smash their way through a dozen skeletons. Lots of these moments make it more heroic when they have to face a Zombie Ogre, bashing at the gates of their Keep. Too often we think of challenging the PCs or players. When everything is a challenge there's no way to accurately gauge your advancement. With kids, you want to make them feel heroic fast. Remember, short attention span. Give them challenges but make them easy. If you notice, I let a lot of the terrain add complications, but victory was all but guaranteed. Then once they're comfortable with combat and danger, you give them a real challenge where they get to test themselves. I got the idea from watching the kids watch Star Wars for the first time. Blasting their way through Storm Troopers, swinging on ropes, sneaking around a star base, and then fighting a trash monster in water with a closing wall trap. That pulp adventure really works well for children, and adults like it too.
