For 4e D&D - which I've also played quite a bit of - I would say:
1. Choose attack
2. Declare target
3. Roll d20
4. Add attack bonus
5. Comare result to target's defence
6. Roll damage
7. Apply damage and any other effect
That makes 4e less complex than RM, and to me that seems right
Hmm. I've run 100s of sessions of both RM and 4E, and my impression is the reverse; For both examples I'll assume a "good" sport of hit -- one that causes a critical or triggers an effect
Rolemaster
0. Declare action (who you attack and how/what attack)
1. Declare attack/defence split.
2. Roll d100.
3. Apply modifiers (attack split, defense, situational)
4. Cross reference on chart to determine hits taken and crit delivered.
5. Roll crit.
6. Cross reference on chart to determine consequence of crit.
7. Apply total hits taken and other crit effects to target.
D&D 4E
0. Declare action (who you attack and how/what power)
1. Roll d20.
2. Apply modifiers (attack bonus, situational) and compare to defense
3. Work out how many damage dice to roll based on d20 roll and other situational modifiers
4. Roll damage dice
5. Work out modifications to the damage based usually on situational modifiers
6. Apply hit/miss/effects for the power
7. Resolve reactions
8. Apply total hits taken and other effects to target
Not only are there more steps, but the details for the 4E ones are trickier (dare I say "more complex"?)
Looking at my current 4E character, here is a completely standard attack sequence:
0. "I attack the stone giant with OPENING MOVE"
1. Roll 19
2. +22 attack, +2 for combat advantage, +2 because the warlord gave me a bonus -- I hit
3a. Since I am using my longsword I will roll a base of 2d8 (referring to both power and weapon information)
3b. I have combat advantage, so I will add 3d8 sneak attack dice
3c. Critical? I did not roll a critical (refer to weapon, which only crits on a 20, unlike my jagged longsword) so no modifications there
4. Roll 5d8 for a total of 26 hits
5a. Standard modifier is +12 (different for each combination of power and weapon -- some attacks are dex based, others charisma)
5b. My goblin totem weapon applies, adding +3 to the damage
5c. As a multi classed fighter, choose whether I want to apply my once per encounter damage bonus
6. Apply the OPENING MOVE effect of a power bonus to my AC and reflex for one turn
7. Anything could happen now, if I'd used a ranged attack, typically the ranger might take an attack right now
8. Target only takes hits damage from this power.
My experience is that RM is significantly easier -- conditional stuff usually applies just to the the attack roll, not to damage calculations, not to extra effects, and so on. The lack of reactions is also huge.
This is not a knock on 4E -- I love playing it, but it is because I
enjoy the complexity! It's a feature!