“What dangers he might meet he could not know, so he selected three spells of general application: the Excellent Prismatic Spray, Phandaal’s Mantle of Stealth, and the Spell of the Slow Hour.” – Dying Earth

Spells and magic items from UA are in play.

The spell acquired by a magic-user upon gaining a new level is chosen by the magic-user. However, the spell must be of a level the magic-user is capable of casting at their new level and the regular “chance to know” roll must be made. If the roll fails, another spell can be chosen until one succeeds.

Spells containing a person's name in the spell title (e.g. Tenser's floating disc) cannot be chosen at any time – they must be found “in the world”, through adventure.¹⁾

When creating a new character, magic-users and illusionists should only roll on and/or select from the spells in the PHB. On level-up, spells from UA can be selected.²⁾

Magic resistance applies to all spells, not just to magic-user spells.

Touch spells with the duration of “one touch” can be held in-hand until something is touched. If the character touches themselves or one of their items with that hand, the spell goes off. Be careful.

A full night’s rest is not necessarily needed to recover spells. Only the amount of time dictated by DMG 40 is required. This means a two full suites of 1st level spells could be easily cast by someone with a day to spare.

If a non-offensive spell is used offensively, such as teleport, the unwilling target is entitled to a save vs spells, and typically will need to be touched for the spell to target them.

While most spells do stack, spells of the same line do not. Only the best benefits from each spell are used. The classic example is bless, chant, and prayer.

Attempting to know a spell via a scroll releases the magic from the scroll. Whether the to-know attempt fails or succeeds, the writing fades from the scroll.³⁾

See Recharging.

Magic circles of protection can be drawn without the use of a spell.⁴⁾ The production and nature of these circles are presently left up to the DM for their own campaign, as no player has ever attempted this in ours. But we'll put a TODO here as something we could set up some rules for in the future.