I'm looking for comparative reviews for Descent vs Doom, especially regarding the strategic aspects and the added value of expansions.
Are the games/extensions of both compatible? To which extent? How much are the games different from one another?
Got 'em both, so I'll give you my feel on the two games, what they have in common, and their differences.
For starters, both games are based on the same game "engine": a miniatures-type boardgame, played out on a unique board made up of individual pieces to form halls and rooms. Most of the players play the "good guys" who win by accomplishing certain goals for that particular scenario (usually, but not always, to escape from the "dungeon"). One player, however, controls the monsters, and he wins by preventing the other players from accomplishing their goals. As such, he is not a neutral "dungeon master" but an active player with his own purposes.
Both games use a special set of dice for resolving combat. These dice are color-coded, and are used in different combinations to represent ranged and melee weapons or attacks. The dice resolve both the range of the attack and how much damage the attack does, so there is no chart or ruler to consult to determine if an attack hits or how powerful it is. The "monster player" gets a deck of cards from which to draw that provides him with abilities like spawning monsters or springing a trap on the heroes.
As far as differences, start with the theme. Descent is a high-fantasy dungeon-crawl, complete with wizards and dragons. Doom is sci-fi/horror, with zombies and demons overrunning a base on Mars.
Doom was the first of the two games, and as such is less complex. The heroes are generic "space marines", with a random card draw or two to add individual skills. Descent lets you start with a unique hero with built-in characteristics, and then further customize with skill cards. Descent also adds "power dice" with which you can upgrade an attack. RTL provides a fully-developed campaign for Descent, complete with character development; some simplified campaign rules are tacked into Doom, but it's nothing like RTL.
Finally, Doom appears to have little support or continued development from FFG. One expansion was released, and one additional "official scenario" was posted on the old website. Descent continues to be supported and new expansions are regularly released.
I didn't initially buy Descent; the theme in Doom was more enjoyable to me and my regular gaming group. However, I purchased the base Descent game and RTL together, and am currently in the middle of a campaign. My group has not played Doom since starting the Descent campaign.
Hope this helps!