Especially at low levels, it can be difficult to find monsters that feel like a boss encounter. Dragon wyrmlings, dire wolves, goblins bosses and other such creatures can go a long way as bosses, but to players who have played at higher levels many times, some of these enemies are creatures they have met many times. What’s worse, they don’t have the legendary or lair actions that make a creature feel like a boss to experienced players.
Improved equipment (including common magical items), legendary actions, and lair actions can be added to appropriate CR creatures to make them a greater challenge and familiar as a boss creature. Consider these options:
Common Magic Items
Xanathar’s Guide to Everything has a lot of good common items, but especially consider potions of healing and scrolls with cantrips or first level spells. These consumables can be a special reward for the PCs if they triumph before the boss can use them.
At low levels, limit the creature to 1, maybe 2, legendary actions per round. These legendary actions, coming after a PCs turn, don’t need to do much to telegraph that the creature is a boss. In order to not significantly increase the challenge of the creature, limit the creature to legendary actions with little combat impact:
- Drink a potion
- Disengage and move 10 ft.
- Attack (2 actions)
Another feature that makes it clear a creature is a boss is having a lair with associated actions. At initiative 20 when the creature uses a feature of the lair, it becomes clear that this is a special enemy. Try to make the actions a sign that this creature is better prepared than the average monster:
- Call for help, smaller creatures arrive in 1d4-1 rounds.
- Trigger a trap-like device that effects the battlefield
- Impose disadvantage on a PC using the terrain or other prior preparation
Lairs also usually come with regional effects that make it apparent that a big bad is nearby, though they may not make sense for a low level boss.
Example: Half-Ogre Bandit Leader
For a party of 4 level 1 characters a CR 1 creature with a couple of slight upgrades makes a sufficiently difficult encounter to call it a boss battle. Consider a half-ogre leading a band of bandits. Give him a potion of healing (2d4+2 healing) and moon-touched battleaxe (XGE). Give him a legendary action each round, usable to drink his potion, move, disengage and move, or call for a bandit arriving in 1d4-1 rounds.
This boss could really make trouble for the party, but he’ll definitely feel like a boss and be a surprise.
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