I know how to create spells on the character sheet that include additional damage at higher levels, as long as it does it every level. Is there an easy way to create a spell that adds damage every two or ever three levels higher? I did multiple google searches about this, but could not find anything addressing specifically this. Thanks in advance!
I assume you're referring to D&D 5e OGL sheet?
I find it best to create custom entries in the Attacks and Spells section. I hate that higher spell level damage is a separate box, my brain prefers to do less math on the fly.
What you can do is set a query in the damage section to prompt you for the spell level when you roll for damage (a spell with an attack roll won't ask until you roll for damage if attack and damage rolls are separate). For instance, for a spell like Chromatic Orb, I set it to roll [[2+?{What Spell Level?|1|2|3|4|5|6|7|8|9}]]d8. For a spell with damage that changes based on every other level, like Spiritual Weapon, you could set it up like this: [[floor(?{What Spell Level?|2|3|4|5|6|7|8|9}/2)]]d8. It'll halve the spell level and round down to the lower value if an odd number level was used, as the spell dictates.
For a spell like Shadow Blade that doesn't follow a pattern, you'd have to manually assign the values in the query thusly: ?{What Spell Level?|2, 2d8|3, 3d8|4, 3d8|5, 4d8|6, 4d8|7, 5d8|8, 5d8|9, 5d8}
Spells Tab:
If you're using the D&D 5e OGL Sheet, it will default a query if there is anything entered in the At Higher Levels: field. As such, you can utilize that query and result to output your own math. So for a second level spell like Spiritual Weapon, you can use this:
[[floor(?{Cast at what level? 2}/2)d8+@{wisdom_mod}]]
Core tab, Attacks and Spellcasting box:
In this field, you can get a bit more clean with the macro.
?{Cast at what level?|Level 2,1|Level 3,1|Level 4,2|Level 5,2|Level 6,3|Level 7,3|Level 8,4|Level 9,4}d8