If the Dreadnought misses his first attack is he stopped from further movement? Also, if the PC makes the strength save does that stop the dreadnought from further movement?
[RPG] How does the Fire Giant Dreadnought’s Shield Charge actually work
dnd-5emonsters
Related Solutions
Curse of the Evil Eye is a separate Action and must be used on its own. It does not happen when only Evil Eye is used.
What Curse of the Evil Eye does is the effect of Evil Eye, plus extra effects on a failed save.
Isn't that strictly better than just using Evil Eye then, though? Yes, but it's a recharge power that can only be used once in a fight, so that's not odd.
No. No. Mostly no.
One at a time:
Can I apply Sentinel rule 1 to a Battlemaster's Riposte?
No. You can't because the Riposte isn't an opportunity attack. Sentinel rule 1 only works on opportunity attacks.
Riposte
When a creature misses you with a melee attack, you can use your reaction and expend one superiority die to make a melee weapon attack against the creature. If you hit, you add the superiority die to the attack's damage roll.
Your confusion on this point is understandable. Ripostes and Opportunity attacks are both (usually) melee weapon attacks that use your reaction. But that doesn't mean that every reaction attack is an opportunity attack.
Sentinel (rule 1)
When you hit a creature with an opportunity attack, the creature’s speed becomes 0 for the rest of the turn.
Sentinel strict applies to opportunity attacks, not Ripostes, Ready Actions, or other attacks that you might use your reaction for.
Opportunity attack
You can make an opportunity attack when a hostile creature that you can see moves out of your reach. To make the opportunity attack, you use your reaction to make one melee attack against the provoking creature.
Opportunity attacks only occur if a creature leaves your reach (or another says otherwise).
If I debuff a creature's speed with Sentinel and trip it, will it be stuck on its next round?
No. The movement debuff lasts for the rest of the turn, not the round (see quote above). A turn is one creature's chance to act. So if a monster moves out of reach during its turn, your opportunity attack also takes place during its turn. As soon as the next creature starts acting, its speed will no longer be 0.
Could I use Sentinel rule 3 and then apply Trip Attack to make the creature prone and have 0 speed?
Mostly no. Again, the attack that Sentinel provides you is not an opportunity attack.
Sentinel (rule 3)
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.
If instead of hitting the rogue, the monster moved out of your reach, then it would be an opportunity attack, and you would be able to trip and debuff their speed. So make sure the rogue knows not to stand right next to you.
Bonus question: Can I use Trip Attack with Sentinel rule 3?
Yes. The only requirement for Trip attack is that you hit with a weapon attack (it doesn't even need to be melee). You can use this with the Attack action, bonus action attacks like Two-weapon fighting, Opportunity Attacks, Sentinel rule 3 attacks or pretty much anything else as long as its a weapon attack.
Trip attack
When you hit a creature with a weapon attack, you can expend one superiority die to attempt to knock the target down...
Different maneuvers have different requirements, so be sure to read each one carefully (for example, sweeping attack requires a melee weapon attack). And remember, only 1 maneuver per attack.
Best Answer
Nothing in the Shield Charge ability's description says that its movement is stopped by its attack during the Shield Charge. From its statblock:
Judging from that, the shield charge lets the fire giant dreadnought move up to 30 feet in a straight line, including through the space of any creature that is smaller than Huge. The attack is essentially incidental to the move; if the target succeeds its Strength save, it is unaffected.
You could flavor this as if the character that makes the save is actually holding the fire giant dreadnought back just long enough to move himself/herself out of the way, or however else you want to describe it.
The dreadnought could, of course, choose to stop before the end of the 30 feet, since the Shield Charge doesn't specify that it must move the full 30 feet.