Sentinel

Complete guide to the Sentinel feat in D&D 5e. Lock down enemies, protect allies, and control the battlefield with devastating opportunity attacks.

Benefit

You can stop enemies in their tracks with opportunity attacks, punish foes who ignore you, and protect allies from harm.

Mechanics

Sentinel provides three powerful defensive and control benefits: **Opportunity Attack Stops Movement:** When you hit a creature with an opportunity attack, the creature's speed becomes 0 for the rest of the turn. This stops any movement they had remaining. **Attack Creatures Who Attack Allies:** When a creature within 5 feet of you makes an attack against a target other than you (and that target doesn't have this feat), you can use your reaction to make a melee weapon attack against the attacking creature. **Ignore Disengage:** Creatures provoke opportunity attacks from you even if they take the Disengage action before leaving your reach. **Important Details:** - Reducing speed to 0 stops movement from all sources (including flying) - You can only use your reaction once per round - The ally protection feature triggers on the attack, not when the ally is hit - Works with reach weapons for 10-foot control zones - Disengage immunity makes you extremely dangerous to flee from

Synergies

Common Mistakes

Common Mistake
Thinking you can use both features in the same reaction - you only get one reaction per round
Common Mistake
Forgetting that allies with Sentinel don't trigger your ally protection feature
Common Mistake
Not positioning yourself between enemies and allies to maximize opportunities
Common Mistake
Missing that reducing speed to 0 stops flying creatures and makes them fall
Common Mistake
Thinking Sentinel lets you make more than one reaction per round
Common Mistake
Not realizing Disengage immunity applies even if enemies Disengage first

DM Tips

DM Tip
Sentinel trivializes many monster tactics - enemies can't just walk past the front line
DM Tip
Intelligent enemies learn to target the Sentinel user or use ranged attacks
DM Tip
Multiple enemies can overwhelm Sentinel (only one reaction per round)
DM Tip
Forced movement (shoves, spells) bypasses Sentinel completely
DM Tip
Sentinel + Polearm Master creates a 10-foot 'no-go zone' that's very powerful
DM Tip
Consider giving enemies abilities that counter Sentinel (teleportation, forced movement)
DM Tip
This feat makes defenders extremely effective at their job

Sources & Further Reading