4th Edition Core Set with Dice Roller

Specific changes in moving to the 4th edition include:
• The alignment system was reduced from nine alignments to five lawful good, good, unaligned, evil and chaotic evil); eliminating lawful neutral, lawful evil, chaotic good, and chaotic neutral, and replacing true neutral with unaligned.
• Revision of saving throws and defense values. Fortitude, Reflex and Will are now static defense values which the attacker rolls against in the same way physical attacks roll against Armor Class. "Saving throw" now refers to rolls made at the end of one's turn in order to end certain ongoing detrimental effects; saving throw rolls generally have no bonus and a DC of 10.
• Changes in spells and other per-encounter resourcing, giving all classes a similar number of at-will, per-encounter and per-day powers. Powers have a wide range of effects including inflicting status effects, creating zones (such as a stinking cloud), and forced movement, making combat very tactical for all classes but essentially requiring use of miniatures. Powers are typically used with particular types of equipment; for example, powers for the fighter class receive bonuses for certain types of weapons, while rogue powers usually require rogue weapons such as daggers and crossbows, and more magical classes can use implements (such as wands) with their powers to add their enhancement bonuses in the same way weapons do for weapon powers.
• In the first Player's Handbook, the warlock and warlord are included, while the barbarian, bard, druid, sorcerer and monk are not present. Of those classes, the first four have been published in Player's Handbook 2, while the monk class appears in Player's Handbook 3.
• Characters at 11th level choose a "paragon path", a specialty often (but not always) based on their class, which defines some of their new powers through 20th level. At level 21, an "epic destiny" is chosen in a similar manner. In many respects, the paragon path and the epic destiny replace the prestige class system of v3.5.
• Core rules extend to level 30 rather than level 20, bringing "epic level" play back into the core rules (level 21+ play had last been explicitly written into core rules in the black-covered "Master" rule set of classic D&D).
• The multi-classing system is revised. Rather than splitting levels between multiple classes, characters properly belong to only one class but may choose feats to gain abilities from other classes. Hybrid characters combine selected features from two classes. Eleventh level characters with sufficient multi-class feats can use "paragon multi-classing" to gain additional powers from another class in lieu of picking a "paragon path".
• Standardized level-based bonus increases. Attack rolls, skill checks and defense values all get a bonus equal to one-half level, rounded down, rather than increasing at different rates depending on class or skill point investment. This bonus also applies to ability-score checks (such as strength checks).
• Revision of the healing system. Each character has a number of daily "healing surges" based on their class and Constitution score. Spending a healing surge usually heals a character for slightly under one-quarter of a character's maximum hit points. Generally, characters can only spend a healing surge during combat by using a special once-per-encounter "second wind" action; however, certain powers allow additional surges to be spent (by the character using it or another character), and characters can spend any number of their healing surges while taking a five minute "short rest" outside of combat. Finally, players recover full hit points after a (once daily) six hour "extended rest".
• Elimination of skill points. Each skill is either trained (providing a fixed bonus on skill checks, and sometimes allowing more exotic uses for the skills) or untrained, but in either case all characters also receive a bonus to all skill rolls based on level.
• Many non-combat spells (such as Knock, Raise Dead, Tenser's Floating Disc, and Water Breathing) are replaced by rituals, which are not class-specific but require a feat (given to certain classes for free) and a skill check to perform. All rituals have a financial cost in the form of material components, such as herbs and alchemical reagents. Item creation feats are also replaced by rituals.
• Elves are split into three races (excluding half-elves) rather than numerous subraces. Eladrin (not to be confused with the quite different monster of the same name in previous editions) are more civilized and magical, while regular elves are agile forest dwellers rather than city builders, and the evil subterranean drow are largely unchanged in flavor. All three elven races are considered fey. Gnomes are also considered fey.
• The Dungeon Master's Guide officially supports leveling monsters down and up to allow for easier encounter design and flexibility. Many monsters have their mechanics redesigned to help differentiate them from others. Some monsters are designed to work well in group fights whereas others can be used as a solo monster versus the players' party.
• Distances previously measured in feet are now measured in five-foot squares; a diagonally adjacent square is considered to be one square away, so effect areas are generally square rather than circular or cone-shaped. The five-foot step, usually taken to avoid attacks of opportunity, is replaced with a type of movement called shifting. Normally a character can shift one square as a move action, but some powers can allow shifting a greater distance or as part of another action.