Giving players debuffs is not fun. Roleplaying being lost is not fun.
I once ran an open world swamp. Over the course of two sessions, players searched for a lost shrine within the confines of my unfilled map. Each hex they moved revealed another part of the bog. Among the fiendish wasps, muddy lizardfolk and grumpy shrub they would face, I wanted a magical mist of confusion.
Attacking the characters and gameplay mechanics would only hinder progression. My mysterious haze needed to interrupt my players' ability to communicate without limiting their stats or take away their abilities yet still managing to increase the difficulty of completing the quest.
Mist of Confusion:
A successful DC 20 Intelligence (Arcana) check alerts players that the mist is magical in nature. The mist can be blown or bottled but cannot be controlled as through the Control Weather spell. Dispel Magic DC 18 removes 40x40 feet of mist that refills over 30 minutes.
Creatures entering the mist must make a DC 15 Wisdom save or become affected by its bewildering enchantment. Once affected, they can only be cured at the bog shrine. Players that successfully save are immune to the mist's effects until the end of the encounter.
D10 Effect or DM choice:
1 Player can only talk in the form of questions.
2 Player can only speak in one word phrases.
3-7 Each of the players' sentences must start with a word beginning with the next letter of the alphabet. For example, this. Got it?
8 Player's statements must rhyme. Extra sentences are not a crime.
9 Player replaces all proper nouns with the word "dragon".
10 Backward sentences their say to has player.
Any player under the effects of the mist that does not speak in accordance with their enchantment takes 1d6 psychic damage.
For the best effect, pass each player a note with their particular ailment, keeping it secret from those yet affected. Some players will take quickly to the game, particularly those that enjoy roleplaying their characters. If you have players who are more focused on combat or lore aspects of the game, give them number 1 or 2. You're not trying to limit how much they speak up, just their communication with the group. Take advantage of their state by giving players a need to communicate. Number 10 is particularly crippling--without proper motivation to speak, the player might shut down, so introduce situations where only one of them can read the ancient writings on the wall or one of them gains important insight they have to share with the group.
A successful DC 15 Intelligence (Religion) check reveals that an otherwise mundane object is in fact an object of spiritual significance. A DC 20 Intelligence (Arcana) check reveals it has lingering magics that could be dangerous.
A creature that comes in contact with this relic must make a DC 15 Wisdom save or be blasted with a bolt of light for 11 (2d10) holy damage. Give the player three lines of dialogue on folded slips of paper so they can’t read them ahead of time. Whenever that player is asked a question or otherwise prompted, they respond by opening one of the papers and reading it aloud.
Ultimately, the fun of this game comes from players' willingness to interact with it. These lines could be simple arcane jargon like, “At three trees stands one, lost but for a star,” but if you relate it to their campaign, the players will enjoy making connections and feel rewarded for applying their knowledge.
These are adapted from Improv conversation games. If your group responds well to these traps, you can expand this concept into other areas. A conversation in a Zone of Silence can play out like charades. A game of "Who am I" can be used as a talking door's riddle. Use these in dungeon and adventure settings to keep RP minded individuals involved. You’ll most likely have one player in your group who would love to be the star for the day and others who would rather continue the combat.