For example, Magic Missile says:
You create three glowing darts of magical force. Each dart hits a creature of your choice that you can see within range. A dart deals 1d4 + 1 force damage to its target. The darts all strike simultaneously, and you can direct them to hit one creature or several.
At Higher Levels. When you cast this spell using a spell slot of 2nd level or higher, the spell creates one more dart for each slot level above 1st.
If a PC finds a scroll of Magic Missile, can it be cast as you would with a level 2 slot (and what are the conditions to do this)? Or will it always be level 1?