An overview of the changes that I’ve noticed between T&T v5.5 and v7.5  All the comparisons phrased in terms of what 5.5 has/lacks vs. 7.5, since I read 7.5 first and went over it extensively.  Also, some of the changes in 7.5 appeared in 5.5 in a couple-page appendix of Ken St. Andre’s house rules:

Chargen

• No WIZ stat, spells are powered by STR.  Advantage: 7.5  STR to power spells isn’t a deal-breaker, but it makes the archetype of the frail old but nonetheless mighty wizard a problem.
• SPD is an optional stat only used for movement rates, which are fairly complicated. It can’t be increased.  Advantage: 7.5  Even if you view Speed strictly in terms of how fast you can run, that’s certainly something you can improve with training, at least as much as you can improve your Intelligence or Charisma.
• No Triples Add and Roll Over. Advantage: 7.5   Not a big deal, but it’s kind of cool. (This is one of the KsA houserules.)
• Weight Possible and Weight Carried emphasized more in 5.5 including rules for how long you can carry how much.  Advantage: 7.5  I’m not enough of a Grognard to value the added bookkeeping.  It’s good to have a rule-of-thumb, but I don’t like tracking it.
• No Specialists or Citizens.  Advantage: 7.5  Anything that increases the number of viable archetypes without unduly burdening the system with complexity is a win in my book
• Warriors don’t get Level adds in Combat Adds. Advantage: 7.5  Something besides the armor bonus as a reward for leveling up is nice to have.
• Warrior-Wizards instead of Paragons. Toss-up. It’s harder to be a Paragon (you need a triple somewhere in your roll-up, not just everything >=12), but the 7.5 advantages are better: they get to double their armor instead of add 1, they get to invent new spells once they reach 10th level, the Wizard’s Guild will sell them spells.  Both versions are rare enough that I doubt it matters which you use.
• No Talents.  Advantage: 7.5. I like Talents…maybe the most out of any skill system I’ve seen published.

Saving Rolls

• Saving Rolls have a minimum for success of 5, and are calculated as the SR – Luck = number to beat (instead of roll +Luck > SR?). Advantage: 7.5   The mechanical result is the same, but roll+add is easier for most people; whether it’s better to have 3 is an automatic failure or <=5 is a toss-up, but I’d personally give the edge to the players succeeding more often.

Combat

• Monster dice as well as adds get reduced as Monster Rating goes down during combat; this produces a much sharper death-spiral effect.  Advantage: 7.5  I don’t really see any advantage to having nearly every combat the PCs win end with several anti-climactic rounds that are rolled (if at all) just to see how fast they can finish.
• 5.5 Makes it clear that armor doesn’t subtract from hits for magic (though a magic amulet might).  Advantage: 5.5
• Missile fire isn’t added into the side’s Total Hits, but some magic is–at least up until the point when it would double-count hits.  Advantage: 7.5  This rule actually puzzles me in 5.5.  If you’re worried about double-counting damage, why does magic get to (semi) double-count and not missiles?  There’s a sort of explanation that Take That You Fiend! jars or shocks nearby foes and makes them less effective, reducing their attack up until it makes them lose the round but never delivering more hits than the magic’s damage, but Freeze Please and Blasting Power are spread out, while other spells don’t, and…It’s far simpler to my mind to just add everything up, and that lets your rear-rank guys like archers and wizards actually figure into whether you win or lose the round.  The whole “the monster can lose the combat because of magic adds, but not take extra damage” calculation makes my eyes water.
• Damage is divided evenly between all the losing side, except that if it doesn’t come out evenly the Wizard (if any) can take the smaller parcel.  Advantage: 7.5   Dividing the damage up is one of the few tactical decisions that the party gets to make during a turn, and I like the idea that the fighters can choose to bear the brunt of it and protect the weaker party members.  I can see play-by-post going with even splits to reduce the back-and-forth, but flavor-wise I think 7.5 is much more interesting.
• Missile weapon fire requires multiplying a distance factor by a size factor to get the SR level, but archers get twice the DEX adds when firing a bow. Advantage: 7.5
• Dodging is handled by an SR against Luck if the players agree that monsters get the same SR. Advantage: 7.5.  There are several points in 5.5 where the rule to be used is negotiated with the players, which I kind of like, but the 7.5 version of just doubling the SR level if the target is dodging or moving erratically is easier and quicker.
• No spite damage.  Advantage: 7.5  Even a stronger party bears some risk of injury in combat, and combats tend to get resolved faster because spite damage bypasses armor.
• Rules for too-heavy weapons.  Advantage: 7.5  While it’s nice that 5.5 has an answer to what happens if you try to wield a weapon too big for you, the answer being that you knock yourself out in short order (your STR is damaged by the difference each round, with it increasing each round as your new STR is even less) is probably worse than just saying you can’t use it effectively.
• Rules for Movement.  Advantage: 7.5  The 5.5 rules are simultaneously complex, with varying formulas based on encumbrance and type of activity (looking carefully, normal dungeon speed, sprinting) and fatigue rules based on CON and abstract, yielding nothing more than a rating of feet/minute traveled.

Monsters

• No special abilities for monsters. Advantage: 7.5  The whole spite-damage activates special monster abilities like stoning gaze or fiery breath makes them a lot less bland, IMO.
• Wandering monsters.  Advantage: 5.5  5.5’s rules are vague, but at least it has some.
• Monster reaction chart.  Advantage: 5.5  Another inexplicable hole in 7.5 is no discussion at all of anything monsters might do except attack and fight to the death.

Magic

• No Kremm resistance.  Toss-up.  I don’t really know whether the whole kremm resistance thing is worthwhile, and I suspect I won’t until I’ve played a bunch.

There’s more, including stuff on learning languages, berserk fighting, a really elaborate set of optional marksmanship rules, hirelings and slaves, some nice discussion of designing a dungeon, and so forth, but that’s the gist of it.  There’s also a fairly substantial (and controversial) change in how experience is allotted, going from advancement in level granting you the right to improve one attribute by an attribute-specific formula (e.g. +your new level to your STR, but only 1/2 your level rounded down if added to your DEX) to a uniform spend your current attribute x 10 xp to raise it by one, with level back-figured from changes to one of your class’ primary attributes, but I haven’t yet bothered to figure out what that would mean for a typical character at various levels.  I suspect 5.5 would tend to preserve initial differences in stats more, since you can only pick one stat to advance per level, and levels take more and more XP to achieve as you advance.

As you can tell, by and large I think V7.5 is an improvement in most ways.  I think 5.5 is a better introduction to RPGs…I’m not sure somebody new to RPGs could really understand what to do with 7.5, and certain things are either cryptic or accidentally ommitted in 7.5 (such as what the 2nd figure for DEX under DEX required for knives meant), but most of the individual rules changes in 7.5 are in the direction of making things simpler and more uniform, and where they add complication (Talents, Specialists) they get a lot of bang for the buck.  Still, I’m very pleased to have both sets of rules now, and I like T&T even more for having read where it is coming from.

update: Commenter G’Noll points out that I was confusing the requirements for Paragon with the other Specialists; Paragons in 7.5 have the same basic requirements as in 5.5: 12+ in every attribute before Kindred modifiers are applied, though that’s much harder to do with an extra two attributes.

Magic in Tunnels & Trolls is a fairly standard (though innovative back in ’76) system of individual spells that cost spell-points to cast.  In earlier editions, your spell-points were your STR, now they’re your WIZ, which seems to me widen the range of possible character types quite a bit.  The names of the spells are whimsical, like “Take That You Fiend!” (the basic magic blast spell),  “Dis-Spell”, “Oh, Go Away!”, which some people find a bit off-putting, but the spell effects are generally straightforward: do damage, turn invisible, heal wounds, and so forth.  Not always: “Troll God’s Blessing” causes a big club to appear over the head of the target and bash it, but if that kind of thing is a problem for your players you can easily substitute more “serious” flavor text.  Spells range in level from 1 to 13 (or more, I suppose, but that’s as far as the books go). Wizards begin with all the standard 1st level spells, and learn new spells from the Wizard’s Guild, by paying 1000 GP per level of spell.  Spells can only be taught by direct instruction (presumably by casting the first level Teacher spell until the Wizard succeeds at the SR to impress it in his mind).  Casting a spell requires a Saving Roll against the level of the spell, which should mostly be a “gimme” except for very low level casters or when trying to cast a spell at a higher level than you’ve reached.

That brings up an unusual feature of T&T magic. While spells have a minimum DEX and INT to cast, they aren’t restricted by the level of the caster.  A 1st level Wizard can attempt to cast a higher level spell, it just requires a harder Saving Roll and higher stat minimums.  A 1st level spell requires 10 INT and DEX, a 2nd level 12, all the way up to 100 for a 13th level spell. Many spells can also be cast at higher level than their minimum in order to ramp up their effects, e.g. Take That You Fiend! costs 6 WIZ and does damage equal to the caster’s INT at 1st level.  If a Wizard with INT 15 casts it as a 2nd level spell, it costs 12 WIZ but does 30 points of damage, as a 3rd level spell it costs 18 WIZ but does 60 points of damage, etc.  Whether a spell can be “Powered Up” and the effects of doing so vary depending on the spell.

Spell costs can be reduced in a variety of ways.  If you’re higher level than the spell you’re casting you get a discount, with a bigger discount the higher level you are compared to the spell level, though there’s a minimum cost of 1.  You also get a discount for using a “focus” such as a wand or ring.  In fact, the primary purpose of wands and staves in T&T is as spell foci rather than bearers of independent spell effects.  Specialist Wizards get to cast all the spells in their specialty at half cost, but can’t cast spells outside their specialty at all. WIZ recovers fairly quickly, 1 point per ten minutes of non-strenuous activity (no combat or running, but you don’t need a lie-down), but high-level spell can still take hours to recover from casting since they can cost 30, 40, 50, even 200 points to cast (for the 13th level “Born Again” spell).

An even more unusual feature, and one that’s apparently new and somewhat controversial, is that spells cannot be directly cast on any target with a current WIZ higher than the caster’s.  That means that not only are Wizards unable to affect more powerful wizards (at least until their targets have expended enough WIZ to make them weaker), but Wizards may find themselves unable to bespell Warriors and monsters if they have built up their WIZ.  Monsters typically have WIZ equal to 1/10 of their monster rating, so a dragon with MR 500 has quite a substantial barrier against direct-effect spells.  Wizards who attempt to cast against a target with higher WIZ get a “bad feeling” that lets them stop before they actually waste any of their own WIZ.

I’m not entirely sure what I think of this.  On the one hand, I certainly see roleplaying possibilities, particularly since spells that indirectly affect the target (e.g. its clothes, or by affecting the ground under it, or drop something on it) are possible regardless of differences in WIZ.  It also gives magic a very otherworldly feel, not at all equivalent to simply having a laser pistol or even crossbow.  On the other hand, since WIZ amounts vary round by round in combat based on the spells the magic users are casting, it might become something of a pain to track, and even if it didn’t you could potentially lose a lot of actions to “bad feelings” when your estimates of the current WIZ of your opponent miss the mark.  On the third hand, it adds another tactical dimension when unleashing a huge spell at the beginning of combat can render you vulnerable to lesser magicians for the rest of the combat, and I’m in favor of increasing the number of tactical decisions, at least in moderation.  As with other things T&T, I really have to see how it plays out in practice.

Here’s a stat-block for a monster from Tunnels & Trolls:

Basilisk MR 78

Here’s the same monster, with the initial Combat Adds prefigured:

Basilisk MR 78  Adds 8d6+39

Here’s a Basilisk with special damage:

Basilisk MR 78 Adds 8d6+39
4/Medusa

4/Medusa means that any turn when it rolls four 6’s in its damage it also uses its gaze to turn someone to stone (as if it had cast the 9th level spell Medusa, though costing no WIZ to invoke).  As far as I can tell, there’s no save…the only thing protecting adventurers from the gaze is the monster needs to roll well in order to use it.

And with some more special abilities:

Basilisk MR 78 Adds 8d6+39
4/Medusa
Healing Feeling (self only), immunity to poisons

Partially Statted:

Basilisk MR 78 Adds 8d6+39
4/Medusa
Healing Feeling (self only), immunity to poisons
INT 27  WIZ 19

Fully Statted:

Gidorah the Basilisk

Basilisk MR 78 Adds 8d6+39
4/Medusa
Healing Feeling (self only), immunity to poisons
STR 18  DEX 32 CON 78  SPD 14  LK 20 INT 27  WIZ 30 CHR 14

I think you get the picture.  Monsters can be described in a single number, or be as elaborate as a player character (not that PCs are all that elaborate), or anything in between as is convenient for the GM and suitable for the adventure.

Run of the mill monsters generally have only one attribute: Monster Rating.   From their Monster Rating you derive their CON (HP) (same as MR), their Combat Adds (MR/10 d6 + MR/2), and their WIZ (MR/10 round up).  As they take damage, their MR drops as do the pluses they get to their Attack, though not the dice rolled.  Unlike adventurers, that means that monsters do have a “death-spiral”–the more you damage them, the weaker their attack becomes.

They can also have additional special abilities to spice things up, like armor, spells, gaze weapons, and so forth. Armor is usually constant, but other special abilities generally trigger when a certain amount of spite has been generated (e.g. the basilisk being able to use its petrifying gaze whenever it rolled 4 or more 6’s on its 8d6 attack).

T&T has a simple rule of thumb for balancing combats… a fair fight is one where the monsters have about the same number of dice of damage as the adventurers.  That might be one monster, or ten.

T&T gets another A from me for the way it handles monsters.  Who needs to “shemp” when you can describe a monster in as little as a single number, or give it a bunch of special abilities, name and personality in one or two lines of text?  For that matter, who needs rules for ganging up, swarms, or over-bearing when a hundred MR 10 goblins are mechanically almost as dangerous as an MR 1000 Titan?

“Combat is the true heart of any role-playing game.” – Ken St. Andre, Tunnels & Trolls v7.5

Combat is the first place that T&T is radically different from what went before…and what came after.  Combat is quite abstract, with turns taking 2 minutes each, during which there is

“probably 10 seconds of action and 110 seconds of maneuvering for advantage.  It can be considered a rapid exchange of strikes and parries by all the fighters involved. By arbitrary convention we stop and evaluate how the fighters are doing at the end of each combat round, but in your imagination you should conceive the action as hot and heavy until such time as the winners win and the losers either lie down and die or run away.”

Magic and missile fire are handled separately, but there is no blow-by-blow accounting taking place in melee combat.  In fact, T&T does away with the to-hit roll entirely.  Instead both sides roll damage, and the side with the lower total takes the difference in damage, spread among them as they like.

So that brings us to another thing about T&T combat: there’s a lot of arithmetic.  A sample combat between two parties of adventurers of 3rd to 5th level involved totaling 4d6+4 + 38 + 2d6+5 +2d6 +3 + 26 + 6d6+3 + 27  for a total of 162.  Then the other party rolls its combination of weapon dice and adds, and gets 154.   Higher level groups and monsters could probably easily see results in the many hundreds or even thousands.

It’s not particularly hard math, and each player except the GM handles a small chunk of it, but there’s a lot of it… if you play it a lot, I can foresee either getting quite good at multi-digit arithmetic or farming it out to a calculator.  For some larger monsters you probably need a dice-roller program even to calculate the damage.  A 3rd level fire-breathing dragon might have 88d6 + 440 as its roll.

For the most part, combat is just that simple.  Both sides roll all the dice for their weapons, add in any combat adds, and then compare.  The losing side divides the damage as they see fit, subtracts any armor, and applies the result against CON.  When a character’s CON goes to 0, they’re dying.  (At -10 they’re dead, dead, dead.)  Allowing the losing side to divide the damage among the characters is interesting; it means that the stronger, more heavily armored characters can effectively protect the weaker characters–at least for a while–and opens up the possibility of mixed-level parties where the low-levels aren’t automatically toast.  Other than that, there are no tactical decisions to be made in standard melee combat.

Magic and Missile fire happen at the very start of the turn, and have the unusual (for T&T) property of directly damaging a particular target as well as counting towards that side’s adds.  There’s also a rule (new in 7+) for “spite damage”… damage that happens despite win/loss or any armor: for every 6 rolled, the other side takes 1 spite damage (again divided as they see fit).  It’s entirely possible, though probably rare, that the losing side does more actual damage after armor than the winning side.  This apparently addresses the problem in earlier editions that even moderate amounts of armor could cause a fight to drag on forever if the parties are fairly equally matched.  Because you can choose specific targets for magic and missiles, this is your opportunity to try to knock out spell-casters and deliberately whittle down the effective members of the opposition, which can cause a steep drop in their side’s total damage if you can pull it off.

At its most basic, there’s not really much room for individual tactics in T&T combat….  It also has a moderately low pace of decision.  At least, it seems to me that unless you’re heavily outmatched, fights will go on for at least a few rounds.  One complaint I’ve seen on some boards is that thanks to armor, evenly matched groups stalemate and the only thing that counts is spite damage.

On the other hand, T&T offers a great deal of scope for rules-light RP modifications to combat.  That is, while there are no specific combat rules to cover any sort of facing, maneuver, special attacks like tripping, grappling, disarming, stunning or the like there is a single rule that you can describe what you’re attempting to do and the GM will give you a Saving Roll to accomplish it and rule on the results.  If you have a Talent that you can invoke, so much the better.  In one of the example combats in the rules, the centaur character decides that instead of attacking with her axe, she’ll try to kick an Ogre to knock it out of combat for a round or two.  The GM rules this is a Level 2 SR vs Dex, and the centaur succeeds by so much (rolling a 45 when she needed 25) that the GM decides that not only is the Ogre stunned and out of commission for 3 rounds, but it takes damage equivalent to the centaur’s Combat Adds.  Everything that crunchier systems handle by specific rules to cover each individual situation, T&T handles by the player specifically describing what out-of-the-ordinary feat they’re attempting to influence combat and the GM ruling on it and giving it a Saving Roll to see if it works.  For a “Rulings, not rules” approach, it’s pretty much perfect.

It’s easy to see why T&T is a success for solo gaming and play-by-post: with no blow-by-blow adjudication or maneuver you can easily and relatively quickly resolve combats even if they involve lots of characters.  And because combats can be resolved without much decision-making if you’re not playing real-time or with a live GM, it’s ideal for the sort of “if you beat the monster, go to 12A, otherwise go to 27B” thing found in solo adventures.  On the other hand, if you have a live GM and bandwidth for everybody to describe what they want to do, the sky’s the limit to what kind of combat you can RP.

Overall, I’d give T&T combat a B.  It’s simple, and flexible, can be explained to someone in a sentence or two, and there’s plenty of scope for clever ideas, though perhaps not a lot of tactics… but the sheer number of dice that need to be rolled and resulting arithmetic is a burden.  Play-by-post, with a handy die-roller, it’s no big deal, but I don’t like to be reliant on something like that for face-to-face play.