I've only ever played or DM'd in a party where all roles were covered once.
From experience, I've found the controller role to be easily bypassed in the game without problems at all. That being said, we did have a fey warlock in the party, who plays a little like a controller in the later levels.
I've had two games in which no one wanted to play a defender. In both these games, we had an armored leader act as the tank (melee cleric, heavily armored warlord). This was also very successful albeit a more tense on the party as the leader was typically most likely to fall first.
I've yet to find a game where in no strikers existed...however, I'm sure the impact would be minimal. Fights would likely last a couple rounds longer but the party would have much greater survivability.
I'm confident that the only thing you must have in a party is one leader. Any other party composition could be played as normal from a DM standpoint.
From experience, I've found the controller role to be easily bypassed in the game without problems at all. That being said, we did have a fey warlock in the party, who plays a little like a controller in the later levels.
I've had two games in which no one wanted to play a defender. In both these games, we had an armored leader act as the tank (melee cleric, heavily armored warlord). This was also very successful albeit a more tense on the party as the leader was typically most likely to fall first.
I've yet to find a game where in no strikers existed...however, I'm sure the impact would be minimal. Fights would likely last a couple rounds longer but the party would have much greater survivability.
I'm confident that the only thing you must have in a party is one leader. Any other party composition could be played as normal from a DM standpoint.