Ultima II: The Revenge of the Enchantress/1990 A.D.

Lord British castle

 * Anytime, anywhere, a guard says: Pay your taxes!
 * In 1990 AD, in Castle British, the merchant orders: Give the King a tribute!

Offering gold to Lord British is the only way to raise and/or restore Health Points.

If your current HP are less than 5000, you will get 300 HP for each 50 GC you pay. Beyond that, you will get 200 HP until you get to 7500 HP, and then just 100 HP per tribute paid. You need at least 850 GC to reach 5000 HP, and at least 2700 GC to reach 9900 HP. Still, you will lose HP fighting the enemies, therefore the above are just lower estimates.

Lord British Castle can be found in 1423 BC and in 1990 AD on the isand of Great Britain. The easiest way to get there from the game start is to enter the Time Gate in East Europe (in 1423 BC). The Time Gate in 1990 AD in Great Britain will bring you back there.

The hotel clerk in New San Antonio

 * In 1423 BC, in Le Jester, the chaste nubile nymph asks: Visit the Hotel California!
 * In 2112 AD, in Pirate's Harbor, the village idiot suggests: Offer the hotel clerk gold!
 * In 2112 AD, on Pluto, in Town Makler, the seaworthy pirate says: See the clerk in New San Antonio
 * In 1990 AD, in New San Antonio, a clerk states: Welcome to the Hotel California!

Offering gold to the clerk is the only way to raise the attributes.

If you offer him at least 100 GC, there is a 50%-50% chance that he will either say "Thank you" or "Alakazam". If he says "Alakazam", one random attribute will be raised a little bit: by 4 units for each 100 GC you offered.

All in all, you need about 24000 GC to raise all your attributes to 99. Since a defeated enemy gives on average 10 GC (and 2 Exp), you have to defeat about 2400 enemies.

How to reach 1990 AD and New San Antonio
First, you need to take a Time Gate to the Aftermath age: From the Aftermath North America, just step away from the Time Gate, then step back into it when it reappears. You will emerge in 1990 AD in South America.
 * 1) from 1423 BC: the gate in South America;
 * 2) from Pangaea Age: the southmost gate;
 * 3) from the Age of Legend: the fourth gate from the left.

Now, how can you get back to 1423 BC and Lord British Castle? In three steps, this time. (1) Go back to the South American time gate: you will emerge in Aftermath age in North America. (2) Step into the south-east North American gate, that teleports to the Age of Legends. (3) Step in the second gate from the left.

Repeat traveling between New San Antonio and Lord British Castle until all your attributes reach their maximum.

All this assumes you cannot use Blue Tassels (either because you own none, or because you are playing a version where they are consumable items). If you can use them instead, you can wait for a pirate ship in 1990 AD and freely travel between the two locations.

Sentri's Quickblade

 * In 1990 AD, in New San Antonio, Santre the Swashbuckler warns: Beware, I've a quick blade!

The above line is the only clue about it, but you can offer 500 gold coins to Sentri/Santre and purchase the Quickblade.

It is the strongest weapon in the game, but its price is very very high regardless of charisma and intelligence. After all, any weapon can harm Minax.