* When creating spells, variable costs can be manipulated in one specific way to increase spell power in a subtle, yet powerful, way. A variable of 1-1 has the same casting cost as a variable of 1-2. A variable of 3-3 has the same casting cost as 3-4. This pattern continues with each increase of pairs of integers, as long as the first integer is an odd number. At mid- to high levels, these small increments can become significant.
* While any three effects can be combined in a given spell, it is easier to combine complementary effects in most cases. Having their durations set the same can also simplify matters. Examples include:
** '''Water Breathing''' and '''Water Walking''' are usually needed in conjunction with one another.** '''Invisibility (True)''', '''Levitate''', and '''Silence''' create a near approximation of a ghostly form.
** A spell that does damage in the '''Area around Caster''' can solve the problem of creatures being "underfoot" when jumping, swimming or levitating down.
** '''Spell Reflection''', '''Shield''', and '''Regenerate''' provide an easily scalable basic defense package.
* Chance of effect should not be neglected with attack spells. Even the most powerful Paralyze spells will be of little help if powerful targets routinely make their saving throws against them.
** Some spell effects, notably '''Paralyze''' and '''Soul Trap''', are all-or-nothing. Chance for these spells should have precedence over Duration in most cases.
* For a [[Daggerfall:Destruction|Destruction]]-based Damage: Health effect, you can choose an appropriate elemental sphere; not only the default Magicka, but also Fire, Frost, Shock and Poison are available. Take the sphere into consideration and make a Destruction spell that corresponds to enemies' elemental weaknesses and resistances.
** Most spells in schools other than Destruction (including offensive, defensive, and utility spells) have Magicka as their base elemental sphere. This creates a lot of confusion among players, as sometimes the Magicka sphere is called simply "Magic". It is therefore important to distinguish between '''Spell Resistance''' and '''Elemental Resistance: Magicka''':
*** '''Spell Resistance''' is an effect which resists ''any'' offensive spell no matter what elemental sphere it is bound to. This effect can be gained by creating and casting a custom protective spell with the eponymous effect, or by increasing your [[Daggerfall:Attributes#Willpower|Willpower]].
*** '''Elemental Resistance: Magicka''' is an effect which resists a Magicka-based offensive spell by nullifying or halving its damage. This effect can be gained by creating and casting a custom protective spell with the eponymous effect, or by choosing either the [[Daggerfall:Resistance|Magic Resistance]] or [[Daggerfall:Immunity|Magic Immunity]] special advantage during character generation.
: This is why the [[Daggerfall:Resistance|Magic Resistance]] or [[Daggerfall:Immunity|Magic Immunity]] special advantages won't really save you against your first imp's '''Wizard's Fire''' attack; only your Willpower and/or corresponding Fire elemental resistance/immunity will (probably) protect you from this Fire-based spell! However, these special advantages should be of use against enemy spells like Silence, since those are purely Magicka-based. Therefore, don't try to exploit the character generation system by taking Magic Immunity and then choosing Fire/Frost/Shock weaknesses to lower the game's difficulty dagger. Once again, Magic Immunity will not override these other elemental weaknesses. However, Magic Immunity is still a very good choice, because, as mentioned earlier, many offensive (mostly non-Destruction) spells are indeed Magicka-based. Also, due to a frequently-exploited bug, Magic immunity/resistance/weakness/critical weakness apply also to Disease, Paralysis, and Poison effects. Thus, due to this bug, choosing Magic Immunity will also render you immune to diseases as well as any paralysis and poison effects.
:* The game normally does not allow you to specify the elemental sphere of your spell if it does not contain a Damage: Health effect, always forcing you to create a Magicka-based spell. However, this can be overcome (mostly for the aesthetic effect of changing the casting animation) by adding a Damage: Health effect after your main spell effect(s), setting the desired sphere, and then deleting the Damage: Health effect. The sphere will remain as long as you don't add any other effects after this procedure. You can in this way safely set yourself as the spell's target and create something like a Fire-based Light spell, which when cast will appear as if you've conjured flames to light a magical candle before you. Unfortunately, while this trick works for spells with one or two effects, it won't work for spells with three effects, for which there's simply no room to 'add then delete' the sphere-changing Damage: Health effect.