One time, from reading these forums, I got the idea that a polearm master + sentinel character would basically be unstoppable. With polearm master he whacks whoever enters his 10 foot range. With sentinel he brings their speed to zero. This wasn't my idea, but rather I read about it somewhere in these forums.
Now that I am more knowledgeable, I'm starting to question this. Is it the community's understanding that there could be multiple opportunity attacks per turn from the polearm master / sentinel? I would have thought that costs him his reaction, and then when he uses it... it's gone (until next round).
You are right. It’s a neat trick, but you can only pull it off once a round. It’s cool, but between only working once, and doing nothing to ranged attacks, it’s not nearly as OP as some think. About the only exception I can think of, and there may be more, is a level 18 cavalier fighter, which gets extra OAs. They can do it all day long. If you ever get to 18.
As Xalthu noted, only once per round. It's not an OP, unstoppable trick BUT it's still a great trick.
Reactions can often go unused each round but both Polearm Master and Sentinel give you a much greater chance of using it. If you go Barbarian - Path of the Giant, then your rage will grow your stature so you cover more ground to reach from AND your reach increases by an additional 5 feet. That gives an enormous amount of coverage and opportunity for using your reaction each and every round, that attack can also help maintain your rage.
Every round you have your Action, Bonus Action, Reaction, Free environment interaction, move, concentration (for spellcasters) and sometimes additional capabilities that cost none of those. It's not everything but its generally good to look out for ways to maximise the use or possible use of every one of those, every turn. If you're primarily a melee fighter, how will you use your Action if no opponents are in melee range? What options do you have for your bonus action each round? What are ways you can increase the likelihood of using your reaction? Can you use movement in special ways that increase your attack power, position you for better actions or avoid attacks?
This is one of the reasons why "Silvery Barbs" is considered an OP spell, not because it can give an attacker disadvantage and a party member advantage, but because its an opportunity to make use of the reaction.
One time, from reading these forums, I got the idea that a polearm master + sentinel character would basically be unstoppable. With polearm master he whacks whoever enters his 10 foot range. With sentinel he brings their speed to zero. This wasn't my idea, but rather I read about it somewhere in these forums.
Now that I am more knowledgeable, I'm starting to question this. Is it the community's understanding that there could be multiple opportunity attacks per turn from the polearm master / sentinel? I would have thought that costs him his reaction, and then when he uses it... it's gone (until next round).
You are right. It’s a neat trick, but you can only pull it off once a round. It’s cool, but between only working once, and doing nothing to ranged attacks, it’s not nearly as OP as some think.
About the only exception I can think of, and there may be more, is a level 18 cavalier fighter, which gets extra OAs. They can do it all day long. If you ever get to 18.
As Xalthu noted, only once per round. It's not an OP, unstoppable trick BUT it's still a great trick.
Reactions can often go unused each round but both Polearm Master and Sentinel give you a much greater chance of using it. If you go Barbarian - Path of the Giant, then your rage will grow your stature so you cover more ground to reach from AND your reach increases by an additional 5 feet. That gives an enormous amount of coverage and opportunity for using your reaction each and every round, that attack can also help maintain your rage.
Every round you have your Action, Bonus Action, Reaction, Free environment interaction, move, concentration (for spellcasters) and sometimes additional capabilities that cost none of those. It's not everything but its generally good to look out for ways to maximise the use or possible use of every one of those, every turn. If you're primarily a melee fighter, how will you use your Action if no opponents are in melee range? What options do you have for your bonus action each round? What are ways you can increase the likelihood of using your reaction? Can you use movement in special ways that increase your attack power, position you for better actions or avoid attacks?
This is one of the reasons why "Silvery Barbs" is considered an OP spell, not because it can give an attacker disadvantage and a party member advantage, but because its an opportunity to make use of the reaction.
Don't forget also that you have to actually hit with your Opportunity Attack for this combo to work. You don't always hit.