Once, in 3.5, I made a mace called Momentum. It cast Death Knell whenever it scored a kill. So .. that was pretty stupid. 

There's no Death Knell in 5e, but at present my new version of Momentum is +1, but adds another +1 for each round in combat. That's still kinda stupid, but not totally outside the realm of reason, since most combats are kinda short. 

But I'm playing a low level campaign. Can anyone come up with a version of this that's suitable for play around ... level 1, maybe level 2? 

Mind, most of the progression in this game will be through magic items, so it's allowed to be powerful. 

It could get +1 for each kill, of course. And/or start at +0, then scale from there. Hm. Opinions?

+1d6 damage per round would be an easy way to scale without it being too broken.

The concept sounds fun, but counterproductive. It makes fights even more likely to be way to easy, or extremely deadly based on good or bad rolls.

Quote from Cheeky_Hamster >>

+1d6 damage per round would be an easy way to scale without it being too broken.

 +1d6 per round sounds worse to me than just +1. But +1d6 for each hit would be kinda cool. If you miss, it resets. That could work.

Quote from Jurmondur >>

The concept sounds fun, but counterproductive. It makes fights even more likely to be way to easy, or extremely deadly based on good or bad rolls.

 At levels 1 and 2, you only get one attack per round. This campaign is long - but it doesn't go anywhere near high level. Once you go there, it spins entirely out of control. But at low levels, you can do silly stuff like this and get away with it. Which is why I'm playing low level =)

If you're looking to just play along the concept of Momentum, you could base the bonus based on the amount the player moved prior to their attack (with a hard cap and wouldn't require tracking the number of rounds) or provide +5 to movement speed each round (seems fun, but probably won't have much impact at early levels especially because movement tends to be most important on Round 1). You could go in a really strange direction and have a bonus based on Initiative (e.g., +3 if you roll higher than 20 for initiative, +2 for higher than 15, +1 for higher than 10 or base it off how many enemies go after you, again with a hard cap).

I mentioned caps, which you could readily apply to your initial concept of a +1 each round by saying that the bonus cannot exceed your Proficiency Bonus. That should keep it fairly well bounded at lower levels.

When you roll a natural 20 on an attack roll with it, it gains an additional +1, to a maximum of +10. When you roll a natural 1 on an attack roll, or are reduced to 0 hit points while wielding it, it takes a -1 penalty, to a minimum of 0.

Quote from I_MAKE_UNBALANCED_HOMEBREW >>

When you roll a natural 20 on an attack roll with it, it gains an additional +1, to a maximum of +10. When you roll a natural 1 on an attack roll, or are reduced to 0 hit points while wielding it, it takes a -1 penalty, to a minimum of 0.

 Considering your nick, I expected something much less ... kinda reasonable. In most cases, this might become the occasional +1 or +2. Rarely would anyone reach +3. However, anyone who attacks with advantage a lot, and also has the ability to reroll critical failures ... well, that's different. 

But anyways, this scales too slowly. It's a neat thought, but I want something that warms up during each fight. For this. I'll keep your idea in mind, it's neat - really =)

Quote from Razmus >>

If you're looking to just play along the concept of Momentum, you could base the bonus based on the amount the player moved prior to their attack (with a hard cap and wouldn't require tracking the number of rounds) or provide +5 to movement speed each round (seems fun, but probably won't have much impact at early levels especially because movement tends to be most important on Round 1). You could go in a really strange direction and have a bonus based on Initiative (e.g., +3 if you roll higher than 20 for initiative, +2 for higher than 15, +1 for higher than 10 or base it off how many enemies go after you, again with a hard cap).

I mentioned caps, which you could readily apply to your initial concept of a +1 each round by saying that the bonus cannot exceed your Proficiency Bonus. That should keep it fairly well bounded at lower levels.

 I wrote a reply for this, but it went ... well, where ever things go on the internet, when they fail for some reason. For mobility, I'd go with boots, not a mace, but otherwise very good idea. 

The initiative thing ... I rather like that. I think I'll make a weapon like that, give it sneak attack as well. A dagger. 

For a twist on the theme of "momentum": As you swing the mace around it builds up more and more force but becomes more and more unwieldy and harder to keep under control.

Mechanically - each time you attack (hit or miss) you get a +1 cumulative damage bonus (up to your proficiency bonus) but a -1 cumulative penalty to your next attack roll. All bonuses and penalties reset if you spend a turn without attacking with the mace.

Would be amusing if the head of the mace actually got bigger and bigger as you fought :)

The weapon is now in the hands of my players. I went with my own idea: It starts at +0, and then get's a cumulative +1 for each round of combat. However, as Razmus suggested, this only works without problems until you reach your proficiency bonus - above that, the mace becomes so fast you take damage from using it, 1d6 pr. round. If you'd like to not take damage, you need to spend a round slowing it back down, taking no actions. Of course, you can also just let go - or even throw it at an enemy. 

Then, in principle, the enemy could pick it up. That could be fun.

Oh - and thanks for all the fun input =D

Quote from Acromos >>

If you'd like to not take damage, you need to spend a round slowing it back down, taking no actions. Of course, you can also just let go - or even throw it at an enemy. 

 What if the mace gained the Thrown property once it reaches that speed? It’d be an interesting incentive for the wielder (and would probably shut up rules lawyers if you have them at your table).

Quote from Kailaidescope >>

 What if the mace gained the Thrown property once it reaches that speed? It’d be an interesting incentive for the wielder (and would probably shut up rules lawyers if you have them at your table).

 Yea - I think that makes sense.