[RPG] How to make someone prone without a shove / strength check?

dnd-5eprone

I want to trip an enemy so he falls prone because our DM made a house rule about prone.

In 5e, trip attack is a specific maneuver that only a Battle Master Fighter (or someone with the Martial Adept feat) can learn. There is also the option to shove someone with a Strength(Athletics) vs. Strength(Athletics) or Dexterity(Acrobatics) check.

Assume a non-fighter without the Martial Adept feat and Strength: 8.

What ways are there to make someone prone with a reasonable success rate? Anything a player can control is fine. Things like magic items that are handed out by the DM are not what I am looking for.

A good answer explains the best ways and quickly discusses the pro and cons of each.

Best Answer

Get creative with improvising during combat.

Fifth edition codifies a list of actions you can take in combat, but these are explicitly non-exhaustive:

The only limits to the actions you can attempt are your imagination and your character's ability scores. [...] When you describe an action not detailed elsewhere in the rules, the DM tells you whether that action is possible and what kind of roll you need to make, if any, to determine success or failure. (PHB, p. 193)

To handle everything else that a character can do, 5e provides DMs with rules for Contests (DMG, p. 238), to be used by the DM as needed to resolve such declarations. The exact two Attribute Checks to make as an opposed roll, and the stakes to be won or lost, are entirely under the DM's adjudication, but based on what you improvise.

So get creative. This edition busts combat options wide open, but it's up to each player to take advantage of that.

But doesn't this step on the Battle Master's toes?

Not at all. The Battle Master's Trip maneuver is strictly superior to just tripping an opponent as it also does weapon damage. It's also much more likely to work than an opposed Attribute Check, as it's an attack roll vs. AC using a Fighter's attack bonuses.