Grounded 4e

NOTE: all the math here has been updated and expanded with a ton more options; see here: http://detectmagic.blogspot.com/2014/03/edition-math-conversion-compendium.html.

There are a number of pretty simple, mostly GM-facing hacks you can do to make 4e play more grounded.

No Math Bloat

These changes make leveling more about new abilities than new numbers. It makes gear much more important. It makes monsters really scary. It probably means you want to use something other than monsters for XP bags (like quest award XP or XP for treasure). 

• Gaining a new level does not by itself grant additional hp
• Remove half level bonuses across the board
• Scaling published skill DCs higher than 19:
• For Rituals with ranges of effect:
• Either leave them alone, to let some ranges be unobtainable at low level, or:
• subtract 19 from the DC
• divide remaining DC by 2, rounding down
• Add to 19 for final DC
• Example (Ritual: Chorus of Truth)
• 19 is the high bound of the lowest range of results. We leave that be. 
• The next range includes 10 results. We reduce that to 5: 20-24.
• The next range is 10 as well. That gets reduced to 5: 25-29.
• The final range is just one number higher and up: 30+. 
• For DCs that are just high because the PCs are presumed to also be of high level: 
• ignore the DC
• just use 11/12/19 range as given in the DM cheat sheet below
• For monsters:
• After determining their level (if converting from HD-determined monsters), either:
• Leave the levels alone, or:
• Remove half their level from their attacks, defenses, initiative, and skill checks

I think I like to just leave them alone and let higher level monsters be really hard to hit.

Converting pre-4e Monsters

To convert an older monster to 4e style:

• damage
• give it damage expressions like so: http://slyflourish.com/master_dm_sheet.pdf
• 1d8+3 + 1/level (1d8+4 at level 1)
• -2 for area
• +2 for limited
• +2 for brute
• +4 for brute limited
• minimum damage for minions
• on top of normal damage, add flat (nonscaling) +1d12 
• this brings the average damage expression to an average of 15
• retain any special abilities (but not multiple attacks probably unless elite or solo)
• determine how much hp it should have:
•  by hand:
• < 1 HD: minion
• HD - X: 7 + 6/level (13 at level 1)
• HD + 0: 9 + 8/level (17 at level 1)
• HD + 1:  13 + 10/level (23 at level 1)
• HD + 2: elite (double a +0 monster's hp, 34 at level 1)
• by the DM sheet above:
• <1 HD: minion
• HD - X: low - 11
• HD + 0: standard - 13
• HD + 1: high - 15
• HD + 2: (low * 2) - 11
• to determine what 4e level a monster of a given HD should be
• HD1 = Level 1
• HD2 = Level 3 (hp = level 1's hp x 2)
• >= HD3 = Level [HD*2]

This preserves the double-hp jump from HD1 to HD 2 and the steadier HP increase thereafter. The increased damage across the board likewise makes the first level much more difficult for PCs. The hp subtraction from monsters makes sure they can go down in a hit or two, as in days of yore. 

Other Tweaks

• All creatures (including your allies) provide cover, and may be struck on miss by 5+. 
• Track encumbrance for real (more in an upcoming post)
• Whenever they take an extended rest, do something bad. 
• Make dungeons dark, apply RAW dim light penalties
• Consider capping advancement at 10 or 11.
• Restock dungeons
• Wandering monsters (10% chance each 10 minutes)