OSE Optional Rules

Hit Point Fairness

Hit points at first level are equal to a maximum roll. When rolling for hit points at any level, the minimum roll is half the die's size. This gives you a more 5E-like experience in hit points per level, but also allows for lucky high rolls as a bonus. You only get one roll of the dice!

• 1d4 = 2 minimum
• 1d6 = 3 minimum
• 1d8 = 4 minimum
• 1d10 = 5 minimum

CON modifiers apply after the roll is determined. Characters, on average, will have about 20% more hit points this way, but on a B/X scale, that will still be on a lower range than 5E. A 9th-level fighter with +2 CON bonus will have about 60 hit points using the standard method, and about 70 using this method.

Heroic Mode Option: Make this half + 1, which aligns these with 5E numbers, but ups the 9th-level fighter to an average of 80 hit points, or 25% more hit points. These were my original numbers, but 80 hit points at level 9 felt a bit on the high side, given OSE's lower hit point totals, and the half-the-die value seemed a better compromise, and a more minor buff, compared to this massive hit point increase.

Racial Level Limit Modifiers

If you are using the optional Character Races rules, modify all racial level limit modifiers by the class's ability score modifier in the class's prime requisite (use the STR table's numbers for all ability scores). So an elven magic user with an INT of 17 (+2 modifier) would have a maximum magic user level of 13 instead of 11.