Players Roll All the Dice
In large combats, players often have little control over the outcome of events when it isn’t their turn. This can lead to boredom if a player’s attention drifts between his turns, threatening to distance him from the outcome of events.
One method of dealing with this problem is to put more dice rolling into your players’ hands: allow your players to make all of the dice rolls during the combat.
Behind the Curtain: Players Rolling Dice
This variant takes a lot of the work out of the DM’s hands, since he no longer needs to make attack rolls, saving throws, or caster level checks to overcome spell resistance for his NPCs and monsters. That can free up his attention for more important things, such as NPC tactics, special spell effects, terrain, and the like.
Conversely, it requires the players to become much more active and aware of what’s going on. No longer can players snooze through all the turns but their own: They’ll be rolling more dice than ever before—which (among other benefits) gives them the feeling of having greater control over their successes and failures.
One drawback is that it takes away some of the DM’s ability to adjust encounters on the fly. Since the DM isn’t rolling the dice, he can’t fudge a result to give the characters a break (or take one away). Thus, it requires him to be more precise in his estimation of Challenge Ratings and encounter levels.
Attacking And Defending
With this variant, PCs make their attacks just like they do in the standard rules. Their opponents, however, do not. Each time an enemy attacks a PC, the character’s player rolls a defense check. If that defense check equals or exceeds the attack score of the enemy, the attack misses.
To determine a creature’s attack score, add 11 to the creature’s standard attack modifier (the number it would use, as either a bonus or penalty to its attack roll, if it were attacking an ordinary situation using the standard rules). For instance, an ogre has a standard attack modifier of +8 with its greatclub. That means that it’s attack score is 19.
To make a defense check, roll 1d20 and add any modifiers that normally apply to your Armor Class (armor, size, deflection, and the like). This is effectively the same as rolling d20, adding your total AC, and then subtracting 10.
Attack Score: 11 + enemy’s attack bonus
Defense Check: 1d20 + character’s AC modifiers
If a player rolls a natural 1 on a defense check, his character’s opponent has scored a threat (just as if it had rolled a natural 20 on its attack roll). Make another defense check; if it again fails to avoid the attack, the opponent has scored a critical hit.
When a PC attacks an opponent, he makes an attack roll against the opponent’s AC as normal.
Saving Throws And Save Scores
With this variant, NPCs and other opponents no longer make saving throws to avoid special attacks of player characters. Instead, each creature has a Fortitude, Reflex, and Will score. These scores are equal to 11 + the creature’s Fortitude, Reflex, and Will save modifiers.
Any time you cast a spell or use a special attack that forces an opponent to make a saving throw, instead make a magic check to determine your success. To make a magic check, roll 1d20 and add all the normal modifiers to any DC required by the spell or special attack (including the appropriate ability modifier, the spell’s level if casting a spell, the adjustment for Spell Focus, and so on).
If the result of the magic check equals or exceeds the appropriate save score (Fortitude, Reflex or Will, depending on the special ability), the creature is affected by the spell or special attack as if it had failed its save. If the result is lower than the creature’s Fortitude, Reflex or Will score (as appropriate to the spell or special attack used), the creature is affected as if it had succeeded on its save.
Magic Check: 1d20 + spell level + ability modifer + other modifiers
Fortitude Score: 11 + enemy’s Fortitude save modifier
Reflex Score: 11 + enemy’s Reflex save modifier
Will Score: 11 + enemy’s Will save modifier
If a player rolls a natural 20 on a magic check, the creature’s equipment may take damage (just as if it had rolled a natural 1 on its save; see Items Surviving after a Saving Throw).
Spell Resistance
If a PC has spell resistance, his player makes a spell resistance check against each incoming spell that allows spell resistance. A spell resistance check is 1d20 plus the PC’s spell resistance, minus 10.
The DC of this check is equal to 11 + the attacker’s caster level, plus any modifiers that normally apply to the attacker’s caster level check to overcome spell resistance (such as from the Spell Penetration feat). That value is known as the attacker’s caster level score. If the spell resistance check equals or exceeds this number, the spell fails to penetrate the PC’s spell resistance.
To beat a creature’s spell resistance, a player makes a caster level check (1d20 + caster level) against its spell resistance, just as in the standard rules.
Spell Resistance Check: 1d20 + SR - 10
Caster Level Score: 11 + attacker’s caster level + modifiers