Dropping backpack

Dropping your pack at the start of combat gives advantage for first round attacks. Keeping it on gives disadvantage for the first round. Dropping it is a free action if you do it when initiative is rolled. If you wait until combat starts, it's a normal action per PHB but I will still give you Advantage on your first attack roll after dropping it. Also, if you get ambushed (sneak attack) it becomes a normal action per PHB to wriggle out of your backpack.

Two reasons for this;

we use the encumbered rule (which reduces movement by 10ft when encumbered) and

loose bags are vulnerable to AoE attacks.

My players actually suggested the idea for this.

"Do I get any bonuses if I drop my bag?"

So you can keep the bag on and protect the gear from AoE attacks but have disadvantage at the start and a reduced movement, or wriggle out of your backpack to gain a quick advantage and better movent but risk losing gear to AoE attacks.

This rule applies to enemies as well. If you see the Orc shake off his pack, you know he's getting advantage on his attack.

2. Rolling 1s on leveling up hps stack with the first non-one.

So if I roll a 1 to increase my Max hps, I get to roll again and add that roll to my 1. If I keep rolling 1s they keep adding.

So for example, if I roll a 1 and then a 2, I add them together for a 3 hp gain.

Or if I roll a 1 and another 1, and then another 1 and then a 4, I add all the 1s to my 4 for a 7 hp gain.

It's not a huge bump up, but it makes those 1s painless.