It is not about memorizing rules. There aren't rules for these keywords, aside one very brief section in the PHB that is about half a page (and which really doesn't say much that is important). It is about being able to see plainly from the description of your Frost Blade that it does indeed add the COLD keyword and damage type to your MBA and thus interacts with your Lasting Frost feat. This is something that in 5e requires parsing dense text of 2 different game elements and then hoping that it isn't worded so vaguely that you still have to consult the DM.
It's very much about memorizing rules.
Looking at Pathfinder 2 here, rather than keeping this about 4e (because discussing that in terms even remotely non-positive will automatically induce an edition war)
CLOAK OF ELVENKIND ITEM 10+
Illusion, Invested, Magical
Method of Use worn, cloak; Bulk L
Activation [[A]] Focus Activation, [[A]] Operate Activation
This cloak is deep green with a voluminous hood, and is embroidered with gold trim and symbols of significance to the elves. The cloak allows you to cast the ghost sound cantrip as an innate arcane spell. When you draw the hood up over your head (an Interact action), the cloak transforms to match the environment around you and muffles your sounds, giving you an item bonus to Stealth checks. If you activate the cloak, you pull the hood up and are affected by invisibility for 1 minute or until you pull the hood back down, whichever comes first.
Type standard; Level 10; Price 1,000 gp
The cloak grants a +3 bonus.
Type greater; Level 18; Price 24,000 gp
The cloak grants a +5 bonus, and invisibility is 4th level. If you're also wearing greater boots of elvenkind, the greater cloak of elvenkind allows you to Sneak in forest environments even when creatures are currently observing you.
Looking at it, the activation uses two keywords and a couple symbol, plus Bulk and the various tags (illusion, invested, magical). There's references to the "Interact" action in the text as well. There's a lot of stuff that is just gobbledygook to new players.
But my favourite bit is at the end where the cloak says it allows you to "Sneak in forest environments". It reads like a plain sentence but the capitalization denotes it's actually some special term. What does it mean? I'm uncertain. It's basically hidden rules.
Or another example, 13th Age.
I was working on making a 5e warlord type class for a while. And looked at the Commande for inspiration. And found its powers awkward to parse.
Buck Up!
Quick action Recharge 16+ after battle
Targets: You and 1d4 nearby allies
Effect: Each target gains temporary hit points equal to the average number of hit points it gains when it heals using a recovery.
Champion Feat Add twice your Charisma modifier to the temporary hit points each target gains.
Epic Feat One of the targets can also heal using a recovery.
I can guess at some of the purposes but so much of how the power works or what it does is hidden in other rules.
That's a barrier to entry and requires system mastery to know what powers do, let alone if they're good or bad.
This is patently untrue. Higher level monsters almost universally have better ACs. Particularly in 2e where monsters with more than 6-8 hit dice are MUCH more powerful, and the 1e quirk of repeating 20 5 times on the attack matrix doesn't translate to THAC0 (meaning that negative ACs are MUCH more effective than in the older edition). I've done the math, even 1e has pretty much the same overall rate of advance in bonus and defenses that 4e has. Albeit things start off a bit worse for the PCs, usually needing a 14 or so to hit, and slowly progress to where they can often hit on a 10 or maybe even an 8 if they're not taking on a top-rung enemy (but forget it if you run into demons or something like that).
You SAY you've done the math and then don't provide it… Proof doesn't work like that.
Do higher level monsters have a lower AC. Okay. Probably. That's going to happen. But the key phrase of my claim was that "the AC of enemies goes up at a matching rate".
Let's actually go to a book. I have the 2e Monstrous Manual handy on my PC so I'll use that.
(Man, I had forgotten how low monster hit points were in 2e. There's some high level critters here that might only have 40hp...)
For low level monsters Goblin is AC 6; kobold is AC 7; orc is AC 6; ogre is AC 5
The hill giant is AC 3. Stone is AC 0. Storm is AC -6. A pit fiend is -5 while the balor is -8. Will o'wisps are -8 for some reason. And the tarrasque is only -3.
But dragon is the big one, with it's AC having a base number that varies by it's age, from -6 for a hatchling to +8 for a great old wyrm. 11
So the difference between a kobold you fight at level 1 and the great wyrm red dragon you fight at level 20 is…. 17.
And that's the most extreme example I can find, with most high level dangerous foes typically only having an AC in the -5 range. If even that.
The fighter's bonus to attack rolls from just THAC0 exceeds the increases to AC. Their accuracy increases.
You don't 'always encounter' such things in 4e either. You are just very much likely to adventure in areas that are thematically, and thus level, appropriate to your characters. In those places most things are possible to overcome with modest luck and a little ingenuity. Its perfectly possible and entirely appropriate and within the rules, for a 4e DM to stick a 20th level lock in front of your level 6 party. They won't get past it, at least not by picking it. Maybe that's the point! The beauty of this kind of setup is, it puts things clearly in the adventure designer's court. Its clear what everything will mean and do within the adventure when its played.
Emphasis added. "It's not against the rules to…."
Yeah… no. That's a theoretical argument. We're not discussing hypotheticals or corner case situations where you throw a great wyrm blue dragon against a level 5 party.
In the overwhelming majority of cases, groups are going to regularly and continually encounter threats and challenges at their level. That's the assumption, and in that case the increased bonuses you have match the increasing DC.
That's how it works in 3e, 4e, Pathfinder, and very likely Pathfinder 2. Where you go from a +5 on a check and a DC 15 to a +25 on a check and a DC 35.
Well, now you have talked to one who has the opposite experience! I'm far from alone, there are dozens of posters on EnWorld who will happily tell you the same thing. Not to mention at least 3 groups of players I ran through campaigns during my 4e GMing.
I think I'll continue to rely on:
http://slyflourish.com/epic/
No bog standard of templatized encounter design is going to counteract that. You have to read more into things. Epic scenarios need to be cast in epic terms.
So do the encounter building rules in the DMG work?
Are five level 25 monsters an moderate challenge for five level 25 PCs?
Is Orcus in the Monster Manual a decent challenge?
There aren't 5 standard monsters worth of opponents in a level 30 encounter, designed to the 'Commander and Troops' template. Instead its Orcus demon prince of the undead with 100 level 30 minion ghouls, a level 29 elite lieutenant, and a bunch of nasty terrain/traps to make the PCs lives hell, combined with some sort of nasty time constraint, plot twist, etc. to turn things INTERESTING!
Well, that answers my above questions, and you admit I was right. That the rules broke down. You could no longer uses the assumed challenges in the book or the rules for encounter building that came with the game.