Spells have no Initiative[/su_permalink] adjustment.
Initiative penalty = Spell Level (min 1); Spell Save DC / Attack Bonus: -1; if done On The Run[/su_permalink], a Steady Focus[/su_permalink] check must be made to execute it (failure = Disadvantage on attack or Advantage on save for target)
Militant Casting: War Wizard feat, Eldritch Knight
DC 15 +spell level [mystic-practice] or spell failure; if done On The Run[/su_permalink], a Steady Focus[/su_permalink] check is required (success = Disadvantage on attack or Advantage on save for target / failure = power manifestation fails); initiative[/su_permalink] is halved
Adjurations are fueled by the bond between a Divine Principal and the caster. These castings are not hampered in any way if the caster has the correct familiarity and/or proficiency with the armor they are using.
Spells are Occult manifestations are require the most freedom from constraint.
Invocations, like Adjurations, rely on external forces of the Pact. These castings are not hampered in any way no matter what armor they are using.
d20 [specific] Requirements: None
If a spell or adjuration is not a Quick Cast type (Bonus Action or Reaction) and armor is worn, it cannot be cast on the run (the Action cannot break up movement - it must be all before or after), and the caster must make a Constitution check to steady up for casting: DC 10 for Medium, DC 15 for Heavy. Unless the caster also uses their Reaction, any spell casting action in Heavy or Medium imposes a penalty to Initiative by reducing it by half in the round you are casting it in. Eldritch Knight (by class) or War Caster (Feat) ignore Steady Up checks if proficient in the armor worn. Eldritch Knights ignore the Initiative penalty as well.