- If you have any choice in the matter at all, play the fan-patch. It updates the game from some of the janky older rules to a more modern set, and drastically expands the card pool. The official site has been down for a while and probably isn't coming back up, but it's not especially difficult to find still floating around.
- Save often, the game doesn't autosave. Try to resist the urge to savescum every time you lose a good card, though. Rolling with the punches is part of the fun.
- Your goal early-game is to get some quests done, collect mana links and amulets, and try to turn your randomly-generated garbage pile into a decently solid, two-color deck.
- Once you've got enough clues that you're thinking of running a dungeon, you'll want to start focusing on building a secondary deck, in different colors than your primary. Certain dungeons will shit all over a specific color or strategy, so it pays to branch out. For example, if your main deck is red/black aggro, you may want your secondary to be white/blue life gain+control.
- Different villages sell different colors of cards, so make that a factor in deciding where to do quests/fight enemies.
- Avoid black if you main white in the early game, one of the enemies for the faction loves creatures with Protection from White.
- All else being equal, blue is probably the hardest faction to fight.
- Keep a couple hundred in gold on you at all times, if you can. Both in case of a shop having a rare card that you want, and so that you have some money to pay off an enemy if the ante is something you really like in exchange for hot garbage.
- If you accidentally cancel out of an opportunity to trade amulets for cards, you won't be able to go back in until the next time it shows up, so make sure you're actually done before you click [Done].
- These tips assume you know how to play MtG. If you have experience with limited formats (Sealed, Draft, Cubes), you'll probably be better at this game than if you didn't.
- Green isn't a terrible first choice for a deck. Good creatures for their cost (both in gold and mana), and Protection from Green is exceptionally rare.
- Black isn't bad, either, creatures with Regeneration are really useful, and black has the most/cheapest by a longshot.
- Don't overvalue any single card, and don't try to 'catch 'em all'. If you've got a rare, valuable card that you can't use right now, probably best to just sell it than to hold onto it hoping that maybe you'll find a deck for it later.
- Stock up on basic land. It's cheap, and you'll need a lot of it. You can ease off once you have 10-12 of a type, but don't be afraid to keep picking it up when there's a good deal after that, just in case you decide you want or need to go monocolor.
- Also stock up on cheap, decently effective cards in your colors. They make good deck filler so there's less chance that your rare, expensive stuff is the only thing getting ante'd.
- When evaluating whether to get cards or a clue after you win, keep in mind that you can also sell rare cards that you don't want.