Warlock spell slots work a little differently than other classes in the 5E RPG. Warlocks don’t have a number of spells they can cast in a day, like other classes do. Instead, they have a number of “warlock spell slots”.
Each time they cast a spell, they use one of their slots. Once they’ve used all their slots, they can’t cast any spells until the next night.
This system makes it important for warlocks to plan their spells carefully. If they know they’re going to be fighting an enemy later in the evening, they might want to cast a spell that will help them survive that fight.
On the other hand, if they know they’re going to be resting for the night, they might want to cast a spell that will help them recover from their battle wounds.
This system also makes it important for warlocks to use their spells wisely. If they have three slots left and decide to cast a spell that requires two slots, they’ll have to wait until the next night to use those two slots again.
If they use those two slots on something else instead, those spells won’t work when needed later in the evening.
Overall, this system seems like it would be difficult for warlocks to misuse their spells. They have to plan ahead and make sure each spell is used wisely, but it seems like it would be difficult for them to accidentally waste their spells.
Overall, this system seems like it would make warlocks more strategic and less reliant on chance when casting their spells.