These are the key concepts and modifiers that make SimpleDnD different from other D&D clones.
d20: Instead of using a ton of different mechanics to represent a ton of different situations, we use one common mechanic to handle ability tests, saves, combat and everything else: roll d20 and add your bonuses! See checks
Rolling Advantage / Disadvantage: Advantage lets you roll 2d20 and take the better result, disadvantage takes the worse. This can be used anywhere that a player rolls d20 – saving throw, attack, or difficulty check.
Initiative: d20 highest goes first. Halflings gain +5 to initiative
Ability Focus: character class specific ability bonus equal to their LEVEL divided by 2 then rounded up.
Hit Bonus: Strength bonus (or dexterity for range weapons) added to hit rolls. If you have Ability Focus, it is added too
Teamwork: Attempting an action collectively allows for one check, using the highest player’s ability bonus AND advantage
Natural 20: In addition a roll of a natural 20 against any check always succeeds.
Critical Hit: Any player rolling a natural 20 in combat always results in double damage (double rolled damage). Some classes can score critical hits on 18, 19 or 20
Notice: Notice is a passive ability (always on) that the DM uses to roll against the players for things like spotting secret doors or ambushes. The number is the Wisdom + Ability Focus (if focused in Wisdom) + 10
Each session to which player attends earns them 1 heroic point that remains with the character. Extra heroics can be awarded by the DM for the playing doing something special or innovative in the game. I’ve been know to award these for a great plan, being in character, and even for and awesome battle result.
The players can then choose to trade there Heroics for the following:
Reroll of a dice roll and keep the new roll
Add advantage to any roll
An additional action in a combat round
Player’s characters should use these points at times of drama (or whenever they want), but we’ve found that they add a great BOOM just at the right moment. Something like that critical attack that slays the dragon or talking their way out of trouble with the city guard.