Looking at running Dead Gods and The Great Modron March, but I'm not sure if I should pick up the AD&D rules or the AD&D2 ones (or AD&D2.5??). Wikipedia helped a little bit but I'm still confused (I started DMing early 3.0). Could anyone give me some advice based on experience on which is best for planescape and what, if any, "optional" rulebooks I'll likely want?
Cheers.
The original Planescape material came out during 2e.
I haven't played/run those particular adventures, but I do recommend 3e/3.5 in general. Also, check out the PSCS on this site.
If you're going to go to an older system - go to 2.5 or 2ed at most - that was the system that Planescape came out under. Going all the way back to 1st won't really gain you anything at all.
If you and your group are already familiar with 3.0 though, then I would stick with that. What you gain with 2e, namely the ease of using the published material, you'll lose due to learning curve with your group.
The difference between the systems is significant. 3.0 was a complete rewrite from the grounds up, and for the better in terms of game play. The rules system of 2nd ed is very soft in terms of balance, and leaves a lot of it up to the GM to figure out what to do. There are a large number of situations that simply have no rulings - leaving you to hack it out on your own. There are also a large number of overlapping and somewhat arbitrary rules as Hyena described. Most of my old groups would drop half of them on the floor for sanity's sake. That's not even to mention the arcane calculations needed for thac0, or the proficiency system (skills? what skills?),completely unbalanced classes and kits, the bizarre XP rewards, weapon speed rules, and odd planar spell limitations that are evocative as setting elements, but hamstring players to the point of being unplayable... For a group that grew up under 3.0 it can be a shock, like going from a slick notebook computer to an abacus.
Which isn't to say that you shouldn't pick up the older modules.
They're extremely well written with some of the most evocative descriptions that have ever been written in the D&D line. The vast majority of the word count of the old Planescape books is dedicated entirely to story. You'll see very quickly why 3.x is accused of being 'dry' and 'uninspiring'. The benefit for you as a GM is that as rules-vague or rules- nonexistant as the older modules are, it makes it much easier for you to divorce the old rules from the setting, soak up the plot, mood, and tone - and bring the 'fluff' over to your 3.0 game.
The PSCS that we have here on the site: /sections/30-/-35-edition
That should get you through the majority of your needs for rules, classes, spells, and the like. For monster conversions that aren't already in the 3.x books, check out the critters section for the denizens downloads.
Yeah, you're really better off going with 3.5 materials and the PSCS here. In addition, I would highly recommend the Frostburn supplement if you plan to run any campaigns in the Paraelemental Plane of Ice, Stygia, Cania, Ocanthus, or Soulfreeze. Of the three climate-setting supplements for 3.5 (4 if you count Cityscape), Frostburn is definitely the best one by far.
The Magic Item Compendium, Spell Compendium, and Complete series (esp. Complete Arcane, Complete Divine, Complete Warrior, and Complete Adventurer) are a must along with the other 4 monster manuals (most of the Planescape creatures from the Outer Planes have been updated in the 5 monster manuals, Manual of the Planes, Draconomicon, and Planar Handbook.)
You'll also want the Manual of the Planes and the Planar Handbook of course. The two Fiendish Codices are also good investments (they cover the Abyss and 9 Hells in depth) Tome of Blood: Book of 9 Swords is also highly recommended, though not necessary.
Bare bones, you'll want the basic 3.5 stuff plus the Manual of the Planes, Planar Handbook, Complete Arcane, Complete Warrior, and the Complete Divine.
You may also want to pick up a few Dragon Magazines. Look at the D&D3 articles in the DragonDex website for anything that interests you.
While the 3.5 rules are largely superior, there are some cautions to be given regarding using them in Planescape, particularly if you want to run the modules based out of 2e rather than your own adventures.
The key point is, that it while it was possible to powergame in 2e, the degree of difference in capability between someone who knew all the tweaks and someone who didn't was nothing compared to in 3.5e, where properly optimized characters dwarf those using inferior 'builds' (I hate that term, it reflects on everything wrong in the spirit of 3e and its successors).
So you'll need to make sure you monitor your characters carefully, especially if they try to brute force features of the old modules (I've never run any of them myself specifically, but DMs had much more directly embedded rules authority in 2e, so there's a likelihood for vulnerabilities) when that would severely rend the adventures.
Yeah, be particularly wary of anyone taking the Cleric as their character class; it is BROOOOOKEN. That's one of the problems with 3x; the classes are even less balanced than in 2E.
To be honest - character classes and choices, and monitoring your players are things you have to deal with in any gaming and any system. Hence why I didn't bother bringing it up.
You've probably got a good handle on your gaming group and already know half of that end of things, esp if you started in early 3.0. You're not green to this 
Don't worry, I'm aware 2e is brutal compared to later editions, that kind of the reason we want to play it. Permanent level and stat drain, save vs death, real cursed items, doors killing you just for looking at them wrong.
It's kind of a backlash after playing a few months of playing 4e (as a player) and realizing how boring it is when everything is safe and player friendly 
If nothing else it will be like a rite of passage lol, play some of the old killer dungeons crawls.
Sounds like 2.5e is where it is at, I was just worried about the political changes like removing half orcs from the phb and all that.
P.S. When I wasn't DM'ing I was one of the people playing a codzilla in 3.5, I know how broken they can be lol In my defence, nobody else would ever play a caster so I made do lol
Oh - you *want* the uglies then? LOL Well then - have at! Once your players get over the proficiency system they'll be whining for mama to bring by her trusty 3.x books again. *pats the stack of books*
Sorry, had to do my old-hand act at least once
If you definitely want to go old school, 2.x is your best bet. For resources: Pick up the basic Planescape books to run with, and the PHB. Anything else will be in the modules. If you have a really magic heavy player set - you might want to pick up some of the magic compendium books.
There are some old 2ed resources on the site here, but they're honestly not that well labeled (project for the future). Review all classes and kits they bring to you - and Know. Your. Spells. Spell levels in 2nd are both more potent and more painful in cost than any later edition. They're also much more flexible and dynamic (I adore 2nd ed's spell list) - so make sure you know what the players have.
For GMing advice, practice your straight-face technique, so they don't know when you had to fudge the rules behind the screen so a flumph didn't kill them. And adjust yourself to characters that have Zero. Skills. Proficiencies in 2nd are rarer than feats in 3rd - so don't over emphasize them - at risk of leaving your players feeling like they're playing the village idiot. You're going to have more backlash from than than from the orcs - guaranteed. (That and you can always retrofit the half-elf or the mul from Darksun into a half-orc pretty easily.)
I'm thinking of just not using non-weapon proficiencies and just calling for ability checks modified by "Because I said so" modifiers. (eg. On the fly decide the ranger gets +4 to an animal handling roll or something similar if the player gives a reason why their character would have that skill).
Seemed out of the whole phb the non-weapon proficiencies were the most restrictive part.
They are really - you may want to do the default stat checks to reflect "basic" knowledge. In a medieval context - knowing how to start a fire or tend a horse are as common as knowing how to drive a car or use a phone are today. Personally I treated non-weapon proficiencies as if they reflected specialist knowledge from a deep level expert in the field.
The proficiency system isn't really that awful. It simply allows each character to be particularly good at a very small number of things, which is what ultimately happens with 3e's overloaded skills system anyway because a combination of too few skill points and too many skills means that characters end up horribly specialized in their skills anyway.
The biggest difference is that there are vastly fewer adjudications to social rolls in 2e, since there's no diplomacy, gather information, etc. This impacts certain styles of play, and certain types of player, way more than others.
if you're going to run the modules, I wouldn't imagine the inter-edition edits would be that big of a deal, especially since a huge portion of the early 3e adjustments was actually incorporating stuff that had been created for Planescape in the base game (if you look at lists of monsters from the PS MCs versus the original 3e monster manual its uncanny). Yeah you'll lose half-orcs, but half-orcs aren't exactly a big part of the planar setting (and if you really wanted, there are 2e stats for them somewhere, Complete Book of Humanoids probably).
The real trick to running 2e Planescape is which of the rules involving spells you want to be draconian in enforcing. The Wizard ones are insanely complicated, but rarely as restrictive as they seem (90% of all spells will still be possible in a given plane, but they may be slightly more or less effective or have weird side effects). The Priest one is the real ***** as that level adjustment, and the resultant loss in 2e's already comparatively reduced healing power can really mess you up. At the very least you should probably use the pantheon rules from On Hallowed Ground or make certain the party healer plays someone with an advantageous god (meaning from the outlands, astral, or other highly linked plane).
Also, make absolutely certain you understand how THAC0 and AC work so that you can handle them quickly. If you do this its is actually possible to make 2e combat run very quickly compared to 3e combat because there is so much less generally occurring (and the fighter doesn't have to bring his calculator to figure out how all his modifiers add up) which is one of the real advantages of the system.
Finally, be prepared for wildness. 2e has far fewer hit points across the board than 3e, but many attacks (particularly direct damage spells, but also some melee attacks) do just as much damage, which means random fluctuations of the damage dice can and will shred your plans.
The no rolls for social interactions is a good thing, I wasn't planning on using them anyway. Isn't the whole point of planescape to be roleplay heavy I'm planning on using the dice as little as possible anyway.
Given your two opinions I'm deffinitely reconsidering non weapon proficiences, though I don't think I'll use than as an added bonus rather than the be-all and end-all of doing out of combat activities.
The hallowed ground cleric rules sound very interesting. I'm definitely going to check that out.
The thac0 and "wildness" issues I don't expect much trouble with
Wildness is more of an issue at mid to upper levels.
For example, a fireball cast by a 12th-level wizard does 12d6 damage in 2e and 3e, for an average of 42 damage. However, in 2e the wizard who casts said spell has an average of 25.5 hit points (9d4+3 for his level, a con-related hit point bonus is unlikely because I believe you need at least a 15 for that to kick in 2e if memory serves), while his 3e counterpart will average at least 42 (12d4 +12 for having a 12 con, possibly more if some other bonus is brought into play).
The clear difference is then: a 12th level 3e wizard can take a fireball from an equal level opponent in the face and almost certainly live, even if he fails to save, while his 2e counterpart is likely to die even if he makes the save if above-average damage is rolled.
That does seem a little steep. Getting casually one hit by a low level aoe spell from an equal level mage seems extreme.
I assume there are long duration defensive spells a well played wizard could cast on themselves to get around this? Or perhaps I could drop a few rings of fire protection into the adventure and then not be a douchebag by casting a lightning fireball or something.
Were there any sort of standard house rules people used to use to get around this sort of thing? I hear 2e unearthed arcana has some good stuff, though I haven't read it yet.
In the day it was mostly just an accepted thing - the mage was squishy, so keep him under wraps as much as you could. There are a number of defensive spells out there, but they start getting pretty arcane. Things like mantle spells - I'm sure there are others, but it's honestly been that long. I usually played multi-class wizard/thieves if i played wizards - and what you can't see, you can't target. Sorry, I wish I was more help on that - I'll take a look through my books tomorrow to see what I can find.
No worries, that's pretty much what I was expecting but I figured I'd check. Most of my ad&d knowledge comes from baldur's gate and the like so I know about mantles and contingencies and what not. It's just my mages used to die in 2 fireballs not one so I got a little worried.
I imagine I'll just recommend that anyoe who rolls caster stats play a multi class for the early hp buff as none of my players really have the hardcore'edness needed to play a good wizard (To much between game research and book keeping for them I guess lol). Any other DMs feel like they could run a perfect game if only they could clone themselves as players?
Mid to high level mages are actually obscenely powerful in 2e if you know how to use one correctly. You are correct that you have protection spells available to prevent you from insta-dying from spells ... likewise the mage gets the best save vs spell in the game, so he consistently takes half damage from attack magics.
As a mage, "Improved Invisibility", "Stoneskin", "Flameshield", "Blink", and "Fly" will be just a few of your best friends.
I have also long fealt that 3x was a game that put its players in straightjackets, leaving them little freedom for creativity; 'everything has to be in the rules' seems to be the tagline ... 2e is much more lenient in this and encourages GMs to device their own ideas and interpretations for things rather than expect the books to have all the answers.
""Permanent level and stat drain, save vs death""
You don't even GET to save vs. death with some things. Take the rot grubs, for instance. There is no save against them. If you don't remove them within 1-4 rounds, they WILL kill you, no if's and's or but's. Not only that, but they're a really low-level encounter. Which is probably why they were never updated to 3x. Rot grubs were a pretty classic monster, though.
Oh, and another thing about the Planescape setting: magic items are your friend. No matter what your character class, you WILL need them. Just hope to whatever diety your character reveres that you don't run into a disenchanter (or anything else that can screw with your magic items.) You definitely want to get your hands on all of the Player's Options, especially Spells and Magic, and Combat and Tactics. Since there isn't a feat system in 2E, the rules in C&T are the only way in which you can do some things (called shots is the only way in which you can target items carried or worn by an opponent). It also introduces a lot of really brutal new rules for critical hits (even more save or die's, you can lose appendages, and nasty blows to the head can result in permanent INT damage) Combat and Tactics also introduced some maneuvers/tactics which became the mainstay of 3x combat (e.g. grapples, disarm, overrun, trip, etc.)
For instance, here's a chart for a critical to the torso:
1–3 No unusual effect
4 Torso grazed, minor bleeding
5 Torso struck, victim stunned 1 round, reduced to 1/2 move with minor bleeding
6 Shield damage, torso struck, 1/2 move & minor bleeding
7 Armor damage, torso struck, 1/2 move, –2 penalty to attacks; if no armor, torso injured, no move or attack, severe bleeding
8 Torso injured, major bleeding, 1/2 move, –4 penalty to attacks
9 Shield damage; torso struck, –2 penalty to attacks; if no shield, torso injured, severe bleeding, no move or attack
10 Torso injured, severe bleeding, no move or attack
11 Torso destroyed, victim reduced to 0 hit points with severe bleeding
12 Torso destroyed, victim killed
13+ As 12 above with tripled damage dice
It also has animal and monster-specific tables.
Yeah, but that chart IS optional - it's not part of the 2E core rules. All the "Official" Planescape material came out during 2E and uses 2E rules, so you (Darvon) will need the 2E Player's Handbook, DM Guide and Monster Manual at a minimum, in addition to the Planescape Campaign Setting boxed set. The Tome of Magic is also very usefull, as is Player's Options: Spells and Magic. I strongly recommend you have the Planewalker's Guidebook, the three Planecape Monsterous Compendiums, the Factol's Manifesto (crucial if you want to play a high-ranking Faction member), In the Cage: a Guide to Sigil (you'll want the added level of detail), Uncaged: Faces of Sigil (great NPCS), On Hallowed Ground (about deities), and Faction War (even if you don't actually play it, the front section has oodles of good info about Sigil). (Actually, you'll want it ALL, but if you're on a budget...) You CAN use all this in a 3E or 3.5 game, but bear in mind that 3rd Edition altered the planar arrangment somewhat (killing off the Deep Etheral and promoting the Demiplane of Shadow to a full-fledged plane, among other changes), however it still uses the Great Wheel and is much more compatable with 2E material than the 4E planes. As to the added risk factor of save vs. die spells and energy draining, I prefer 4E precisely BECAUSE I don't have to recalculate my character's stats after every encounter with a vampire or some such. I saw that as one of the flaws of 2E - 3E, but whatever floats your boat...
We're going back to 2e because playing a year of 4e made us realise how boring it was winning every time with no risk lol. There is literally nothing in 4E that can negatively effect you for more than an encounter, even the extremely rare death is a triviality. Also, the way magic items are handled in 4e is so awfully boring and safe and "scientifically fair" that I hope someone got fired because of it lol.
I imagine after a year or two at the other extreme of the spectrum and getting reamed every other fight we might split the difference and go back to 3e
While I also consider 3ed a superior system to 2e in general, I have to disagree with some of your reasons. Sure, balance was not an issue in 2ed - and that may be a problem or not, depending on your style of play. However the very fact that 2ed leaves a lot up to the GM is one of its major appeals, if compared to the newer editions. Even if 2e didn't have nearly as many rules for all sorts of situations like 3e does, I always felt like I had more freedom in that system, because it was so open ended and free form, especially in relation to social interactions.
And thac0 really didn't need arcane calculations, I don't know why so many people are befuddled by it. All you had to do was check your thac0 score on a table based on your class level and add or remove numbers depending on the target's AC. But yeah, sure. I do prefer the 3e system for calculating attacks better. It's more streamlined.
And to me, the Planescape spell limitations by plane is soooooo much more interesting and dynamic than the dull impeded/enhanced magic thing. I've played my last 3 PS campaigns in 3ed, but I used the 2e PS spell limitations in all of them. My players had to be more attentive and do better research and preparation prior to planar hopping. There were more elements to be taken into account, it added a new layer of complexity to the plots. If you're creative, these limitations can actually become interesting story elements and plot hooks. I also totally ignore 3e spells such as "avoid planar effects". I dislike these 'push-one-button-and-you're-ready-to-go" types of fixes. But then again we always approached our games with the mentality that the journey to get there was half the fun.
I agree. A DM can still be creative in 3ed, but the rules do not encourage it as much as they did in 2e. However, as I said, I still think that despite its limitations, the 3ed rules were an improvement (although I house rule multiclassing in my own games to avoid abuses).
As far as the Player's Options books are concerned, it seems to me that you're going back to 2e because your group is craving a different gaming experience. If that's the case, I would avoid them. They will just make your 2ed game more similar to 3ed. Add more rules, skills, combat maneuvers, etc. I don't think that's really needed for a PS game. The Planewalker's Handbook is a good call though, for its belief point system.
The free form social interactions have their pluses and minuses, and which system is more advantageous can have a lot to do with the type of players in a particular gaming group.
Having no rules for social interactions can mean that a player with an assertive personality, quick lip, and evocative verbal descriptions can take huge advantage of the lack of numerical rules, often without even realizing it. Particularly it allows players to assert themselves in ways their characters, who have low stats in the particular areas should not be able to do.
In 3e, if the half-orc barbarian with a Int 8, Cha 6 and no points in the relevant social skills starts giving an impassioned legal defense the DM can very easily call him/her on it. In 2e its somewhat more difficult, so the DM has to be more assertive and more willing to say 'no you can't do that because I said so.'
The converse is also true, in that it is much, much easier for a somewhat shy, not-talkative player to have a socially adept character function when there are roles for it like in 3e 'Um...I say something about the trade agreement and I role my bluff check' than in 2e, where a DM really has to work hard to draw them out.
Many DM-oriented supplements (notably 'storytelling' chapters in some White-Wolf supplements) address this issue explicitly and provide a wealth of useful advice, though experience and knowing your gaming group are the best teachers. 3e was designed for younger, less experienced gamers (thac0 was explicitly crafted so that people would need to understand how to add negatives, meaning at least high school level math to be able to play) and thus uses a stricter set of rules as a way of protecting the gaming experience from hijacking.
I _wish_ I had the problem of players roleplaying in excesses of their character's int/cha.
Don't forget Wisdom!
Where is that "Priest of Total Wisdom!" Dork Tower comic when I need it?
But it is entirely within the GM's ability to adjudicate this ... I have had to on rare occasion, but thankfully the people who are well spoken in my group are typically those who take high mental scores.
That's true, but I used to have a house rule in 2e (actually I don't remember if this was an optional rule somewhere) to address this issue. During social interactions the player would, before anything else, roll his charisma. That initial roll would determine the NPC's initial attitude towards him (hostile, friendly, indifferent, etc.)
But then it was up to the player to roleplay and talk to the NPC, come up with his own ideas and whatnot. I would base the outcome of the interaction on the initial attitude of the NPC towards him, but also on what kind of story the PC came up with. Only an _extremely_ good story could sway hostile NPCs, but it didn't take much for a friendly one to be persuaded.
In 2e this wasn't that much of an issue, because a high CHA or INT score doesn't necessarily mean the PC is a very good conversationist. Maybe he's just charismatic in a more intangible way. However in 3e this becomes more of an issue because of skills such as bluff and diplomacy, that specify whether the PC is a good conversationist or not.
Let me first say Darvon that I like the way you think when it comes to playstyle. I am all about flexible gaming with on the fly mechanics. I hate the straightjacket of rules heavy systems. Consciously or not, people tend to fall back on rules if they are built in.
I would personally strongly discourage the use of the Players Option books. They were, IMO, completely awful. The system was very poorly designed, created severe power imbalances between the classes, and was open to incredible abuse. It was like the poor mans 3e with all the abuse and none of the streamlining. Sure it gave you more rules for stuff, but the rules were awful.
As far as handling the problems associated with wimpy Mages and Priests suffering from lowered levels, I've always solved that little problem with one shot items, both magical and mundane. The advantage of this solution is that, by virtue of being one shot, they prevent MOnty Haul syndrome, while still giving the party some tricks to help deal with difficult situations. Party run into a pyromaniac mage? Well, that Brimstone Tablet the party bought from Frenns Apothecary for 30 gp is made of sulfurous ash harvested from the slopes of Gehenna and acts as a ring of fire resistance for 2 turns when swallowed. Only problem is, an hour later, the person who imbibes it starts vomiting uncontrollably for 1 turn, and is completely incapacitated. They beauty of Planescape is that there is a creative solution to every problem. It's easy to make a quirky little item like that on the fly for the party to strategically stumble across so they will be prepared for the little nasties you throw at them. The real trick is letting them think they came up with the idea themselves. When they tell you they are going to stock up on supplies, you mention a new booth in the bazaar that just so happens to stock a few things that will help them in a later encounter you've planned. So long as the party is judicious in the use of these trinkets, they should be able to make it through those otherwise dangerous encounters.
Also, as was mentioned, there are actually quite a few defensive spells that really make a difference when playing a mage or a cleric, with the cleric often being able to extend these benefits to other party members. Desperate mages can throw up a Rope Trick and scurry away if things get too harry for example. Stoneskin makes a mage virtually invincible to mundane weaponry. A clever use of a phantasmal force may be able to simply confuse the enemy or scare them away. I once used a simple Diminish spell (reversed enlarge) to create a bottleneck for Goblins boarding a ship. One of the boarding planks was disabled with a low level spell, halving the number of goblins able to attack, and allowing us to make easy work of those still foolish enough to attack, eventually disheartening and routing those waiting for an opportunity to board. Mages in 2e have all sorts of possibilities for defending themselves. You just need to be creative.
Point is, a canny mage will always have a few defensive spells in their spellbook because if they don't they are unlikely to last long in an adventuring party. It's common sense that a frail scholar of the arcane arts should respect his weaknesses and take a few extra precautions. These aren't ivory tower wizards here. They don't have the luxury of an impractical spell selection. Also, the mage-thief mutliclass is often a good combo as I think Clueless mentioned. Nothing like slinging spells from the shadow to make your life easier, and longer!
Basically, 2e to me is all about creativity. You practically have to think beyond the rules. If you ask me, that's a good think. It makes each item and each spell and each experience unique. It beats the rather bland and ubiquitous +2 sword.
>>I would personally strongly discourage the use of the Players Option books.<<
I will second this; the Players Option books were unbalanced and awful.
>>Mages in 2e have all sorts of possibilities for defending themselves. You just need to be creative.<<
Playing a mage could almost be an art form in 2E - I always loved doing it.
>>Basically, 2e to me is all about creativity. You practically have to think beyond the rules. If you ask me, that's a good think. It makes each item and each spell and each experience unique.<<
And there you have the reason I've always prefered 2E over Third Edition; and the magic items were so much more interesting.
Oh that's good. I'm stealing that one.
With the mage issue, super squishy I'm fine with, but defending against a low level aoe spell that gets thrown about like a stock attack that does double your hit points in damage was worrying. Sounds like it shouldn't be too much of an issue though if the player is smart and the DM isn't an arse.
And magic items? God yeah. My favourite part of the infinity engine games was reading the item descriptions. My favourite 3e book was the magic item compendium. Volo's Guide to All Things Magical is just one of my favourite books; period
BTW, if you have any plans for playing a ranger, I would strongly suggest the Complete Ranger's Handbook, as it has a pregenerated stat roll table (it's almost impossible to get the stats you need to start out as a ranger) It also has a few additional ranger spells. The ranger's spell capabilities suck, though. Unless you're playing a Faerunian ranger (actually, one of the nifty things about Planescape is that you can start out in any setting you want except for Ravenloft or Dark Sun, and then planeshift into the Planescape setting.) which also gets the traveler's domain, you're limited to two domains at up to level 3 spells, while the Paladin gets four domains and up to level 4 spells (five domains if he's a faerunian paladin)
The only way to get better casting power for the ranger is to take the seeker kit, and it sucks horribly (too many limitations just so you can cast 4th level spells.)
I think Planescape uses AD&D 3.5 rules, but I could be wrong.
As for supplements, you will want the Tome of Magic and all three of the Player's Option books. There are also quite a few class-based handbook accessories, some of which are better than others (the Ranger's, Druid's, and Wizard's handbooks are very, very good, and the Cleric's handbook has a few guidelines and ideas for creating your own dieties/specialty priests.)
There are a few things that you should be warned about.
2E is a lot harder than 3E, especially Planescape. There are a lot more "save or die" situations, and the Planescape rules are much more difficult.
In 3x, you basically have enhanced and impeded magic, where (IIRC) impeded magic only works about half as well as it would otherwise. For instance, if you're on the Paraelemental Plane of Ice, magic with the fire subtype will be impeded.
Now, in Planescape, you have four types of effects (again, I'm going off of memory here). Magic can be mildly enhanced, greatly enhanced, impeded, or not work at all.
For instance, on the Paraelemental Plane of Ice, earth-based magic will only be half as effective (since the earth plane is on the opposite side of the inner planar cosmology), while fire magic doesn't work at all. The only way to get around this is to use something called a 'spell key'. Also, the inner and outer planes in 2E/Planescape arent' connected at all. This means that while you're on the Inner Planes, you're treated as 3 levels lower if you're a divine caster and your diety resides on the outer planes and you try to use your spells.
It also means that you can't summon anything from the Outer Planes while on an Inner Plane and vice-versa. It's worse than that, in fact. You can only summon creatures from adjacent planes. In other words, if you're currently on the Abyss, you can only summon creatures from the Abyss, Carceri, Pandaemonium, the Outlands, or the Astral Plane. Bear in mind there is no fiendish or celstial template in 2E (not that I can recall, anyway), so you're more limited in what you can summon.