So I've been playing dnd for many years now but always as a player. I am now DM'ing my first campaign using an old turn-based RPG I used to play when I was little for the storyline. Everything is going well except combat. I have 2 of my players that built their own characters from scratch and are around the same power level, then I had one player look up "How to break rogue in 5e" and just built his character so it would be the most OP. So I have a mediocre Paladin and Cleric, then I have a super OP crossbow wielding rogue that can attack 3 times in one turn, has +13 to hit, and gets sneak attacks if he stands behind allies. If I balance the enemies for the rogue, the two other characters struggle to survive, and if I balance the enemies for the other two, the rogue just slices through them with zero effort.
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