My group's warlock/paladin isn't determining spell slots correctly, treating the warlock as just anoher spellcaster.
Care to elaborate? I don't have a warlock/paladin yet but someone is thinking about it for our next campaign.
I am sure you are right there.You're not going to spot the DC 15 detection pit trap with a PP of 17 using dark vision in total darkness, though.
Bonus action to drink a potion is one that I've seen come up a fair bit.
To me its more of a matter of information.
It's wrong if a DM says "This is the way the rule is written."
It's right if a DM says "This is how we are playing this at my table."
Many DMs and players do want to stick to the rules whenever possible and are simply making mistakes. Interpreting the rules incorrectly is a mistake if you believe you are following the book and are not. As a player I am much more confident in a DM who explicitly states "We are going against the written rules because I think it works better for my table like this." than one who states "No, this is what the rules are." when there is a conflict between expected interactions in game.
DM's always have the final say at the table, but should be open and honest with their players with the DMs various intentions of the game. Such as: adult themes or language, serious vs light-hearted, rules strict or loose, social engagement, combat engagement, inter-party conflicts,mortality of players. All of these aspects should be made clear to the players early on so they know what they are getting into before they have many hours invested.
Further notes: Most races state in their darkvision description that darkvision allows sight in dim light as if it were bright and in darkness as if dim. The darkvision description says that you see darkness as if it were dim light and only in shades of grey. This means a vision based check for a character that has darkvision looking in darkness (within the range of the darkness) has disadvantage (which results in a -5 to passive scores) and may result in an increase to the DC if the detail to be noted is not visible easily when everything is seen in shades of grey.Racial Darkvision allows you to see in Dim Light as if it were Brightly Lit.
It's not that unclear, is it? It says right in the PHB, "Drinking or administering a potion takes an action" (PHB, p. 144). That's under the Potion of Healing entry in the Equipment chapter.To be fair, that's not at all clear without the Sage Advice ruling. Drinking a flask of water is absolutely covered by the Use an Object action, so it's perfectly natural to assume that drinking a potion of healing should be no different. There's certainly no in-game reason for that to be the case, and, frankly, given the power level of potions in the game it's really not a restriction that I would consider beneficial to retain. It's not at all clear that the individual rules for each magic item type or each individual magic item description are providing explicit exceptions to the normal combat action rules. If Mearls and Crawford had wanted the game to work this way, they should have added a Use a Magic Item action to the list in the PHB.
It's not that unclear, is it? It says right in the PHB, "Drinking or administering a potion takes an action" (PHB, p. 144). That's under the Potion of Healing entry in the Equipment chapter.
I'm not sure where "drinking a flask of water" comes from,
unless you mean "drink all the ale in a flagon" in the Combat chapter. In which case I agree that "drink all the ale in a flagon" is a terrible example of what you can do in tandem with your movement and action. It can only be rationalized if you assume that the flagon is on hand, while the potion is in a backpack and has a stopper.
Activating an Item said:If an item requires an action to activate, that action isn't a function of the Use an Item action, so a feature such as the rogue's Fast Hands can't be used to activate the item.

(Dungeons & Dragons)
Rulebook featuring "high magic" options, including a host of new spells.