D&D spell slot tracker

A spell slot is spent when you cast a spell of that level or lower — casting a 1st-level spell using a 3rd-level slot is legal and often desirable, because many spells scale when cast at a higher level. Slots do not convert; you cannot trade two 1st-level slots for a 2nd.

Cantrips cost no slot at all and can be cast freely. Rituals cast with the ritual tag take ten minutes longer and also cost no slot, which is why detect magic and identify are so often cast that way.

Everything except Pact Magic recovers on a long rest. Warlocks get theirs back on a short rest, which is the entire design of the class: fewer slots, always at the highest level available, refreshed several times a day.

A warlock does not have a spread of slots across nine levels. They have one, two, three or four slots, all at the same level, and that level rises as they do — reaching 5th-level slots at character level 9 and never going higher through Pact Magic itself.

Every warlock spell is therefore cast at the highest level they have. A level 9 warlock casting hex is casting it with a 5th-level slot whether they want to or not, which makes upcasting automatic rather than a decision.

Mystic Arcanum covers 6th to 9th level spells separately: one spell of each, cast once per long rest, outside the slot system entirely. It is not modelled in the tracker because it is a per-spell resource rather than a pool.

A multiclassed caster does not add their two classes’ slot tables together. Instead you work out a single combined caster level — full caster levels count fully, half caster levels count as half rounded down, third caster levels as a third rounded down — and read the full caster table at that level.

So a Paladin 6 / Sorcerer 4 has a caster level of 3 + 4 = 7, and gets a full caster’s slots for level 7. Spells known and prepared are still tracked per class, at that class’s own level — only the slots are pooled.

Warlocks are the exception again: Pact Magic slots stay entirely separate and are added alongside, not merged. A Warlock 3 / Wizard 5 has a wizard’s level 5 slots plus two warlock slots that come back on a short rest.