A few years back, Rob Schwalb did an experiment on his blog: he took bits of the 4e cleric and reformatted them to match the visual look of previous editions of D&D. Since a couple of my players were coming from long-running 4e games (even though they played 3e before that), I decided to do the opposite: take bits of a 5e class, and reformat it to match the visual cues of 5e. I did this mainly to explain the current spellcasting system, where you prepare (or simply know) spells, and power them through spell slots (without losing the prepared spell).
The major breakthrough was turning the actual Spell Slot into the "daily power" (or "encounter", in the case of a warlock), with the effect being left to the spell the caster chooses to invest the slot into. Cantrips, on the other hand, match the 4e at-will structure as-is (with the actual cantrip being the "at-will power").
The major breakthrough was turning the actual Spell Slot into the "daily power" (or "encounter", in the case of a warlock), with the effect being left to the spell the caster chooses to invest the slot into. Cantrips, on the other hand, match the 4e at-will structure as-is (with the actual cantrip being the "at-will power").